diff --git a/config.go b/config.go
index 4816e67..2ad6021 100644
--- a/config.go
+++ b/config.go
@@ -4,11 +4,11 @@
 // you can manipulate a `ssh_config` file from a program, if your heart desires.
 //
 // The Get() and GetStrict() functions will attempt to read values from
-// $HOME/.ssh/config, falling back to /etc/ssh/ssh_config. The first argument is
+// $HOME/.ssh/config, falling back to /etc/ssh/ssh_config (on linux). The first argument is
 // the host name to match on ("example.com"), and the second argument is the key
-// you want to retrieve ("Port"). The keywords are case insensitive.
+// you want to retrieve ("Port"). The keywords are case-insensitive.
 //
-// 		port := ssh_config.Get("myhost", "Port")
+//	port := ssh_config.Get("myhost", "Port")
 //
 // You can also manipulate an SSH config file and then print it or write it back
 // to disk.
@@ -35,7 +35,6 @@ import (
 	"fmt"
 	"io"
 	"os"
-	osuser "os/user"
 	"path/filepath"
 	"regexp"
 	"runtime"
@@ -47,95 +46,53 @@ const version = "1.2"
 
 var _ = version
 
-type configFinder func() string
+type ConfigFileFinder func() (string, error)
 
-// UserSettings checks ~/.ssh and /etc/ssh for configuration files. The config
-// files are parsed and cached the first time Get() or GetStrict() is called.
-type UserSettings struct {
-	IgnoreErrors       bool
-	customConfig       *Config
-	customConfigFinder configFinder
-	systemConfig       *Config
-	systemConfigFinder configFinder
-	userConfig         *Config
-	userConfigFinder   configFinder
-	loadConfigs        sync.Once
-	onceErr            error
-}
-
-func homedir() string {
-	user, err := osuser.Current()
-	if err == nil {
-		return user.HomeDir
-	} else {
-		return os.Getenv("HOME")
+// UserHomeConfigFileFinder return ~/.ssh/config regardless of your current os,
+func UserHomeConfigFileFinder() (string, error) {
+	osUserHome, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
 	}
-}
 
-func userConfigFinder() string {
-	return filepath.Join(homedir(), ".ssh", "config")
+	return filepath.ToSlash(filepath.Join(osUserHome, ".ssh", "config")), nil
 }
 
-// DefaultUserSettings is the default UserSettings and is used by Get and
-// GetStrict. It checks both $HOME/.ssh/config and /etc/ssh/ssh_config for keys,
-// and it will return parse errors (if any) instead of swallowing them.
-var DefaultUserSettings = &UserSettings{
-	IgnoreErrors:       false,
-	systemConfigFinder: systemConfigFinder,
-	userConfigFinder:   userConfigFinder,
-}
+// UserSettings checks all files listed via configFiles.
+// The list of available files will be traversed from begin to end.
+// The first file which holds the desired key will be used.
+// The config files are parsed and cached the first time Get() or GetStrict() is called.
+type UserSettings struct {
+	IgnoreErrors bool
 
-func systemConfigFinder() string {
-	return filepath.Join("/", "etc", "ssh", "ssh_config")
+	configFiles []ConfigFileFinder
+	configs     []*Config
+	loadConfigs sync.Once
+	onceErr     error
 }
 
-func findVal(c *Config, alias, key string) (string, error) {
-	if c == nil {
-		return "", nil
-	}
-	val, err := c.Get(alias, key)
-	if err != nil || val == "" {
-		return "", err
-	}
-	if err := validate(key, val); err != nil {
-		return "", err
-	}
-	return val, nil
-}
+// DefaultUserSettings is the default UserSettings and is used by Get and GetStrict.
+// It checks both $HOME/.ssh/config and /etc/ssh/ssh_config for keys (on linux) ,
+// and it will return parse errors (if any) instead of swallowing them.
+var DefaultUserSettings *UserSettings = nil
 
-func findAll(c *Config, alias, key string) ([]string, error) {
-	if c == nil {
-		return nil, nil
-	}
-	return c.GetAll(alias, key)
+func init() {
+	defaultSettings := UserSettings{IgnoreErrors: false}
+	DefaultUserSettings = defaultSettings.WithConfigLocations(DefaultConfigFileFinders...)
 }
 
-// Get finds the first value for key within a declaration that matches the
-// alias. Get returns the empty string if no value was found, or if IgnoreErrors
-// is false and we could not parse the configuration file. Use GetStrict to
-// disambiguate the latter cases.
-//
-// The match for key is case insensitive.
-//
-// Get is a wrapper around DefaultUserSettings.Get.
-func Get(alias, key string) string {
-	return DefaultUserSettings.Get(alias, key)
+// WithConfigLocations sets the list of ssh_config files to be searched when using Get, GetAll, GetStrict or
+// GetAllStrict. The list will be traversed from begin to end; the first file which holds the desired key will be used
+func (u *UserSettings) WithConfigLocations(finders ...ConfigFileFinder) *UserSettings {
+	u.configFiles = finders
+	return u
 }
 
-// GetAll retrieves zero or more directives for key for the given alias. GetAll
-// returns nil if no value was found, or if IgnoreErrors is false and we could
-// not parse the configuration file. Use GetAllStrict to disambiguate the
-// latter cases.
-//
-// In most cases you want to use Get or GetStrict, which returns a single value.
-// However, a subset of ssh configuration values (IdentityFile, for example)
-// allow you to specify multiple directives.
-//
-// The match for key is case insensitive.
-//
-// GetAll is a wrapper around DefaultUserSettings.GetAll.
-func GetAll(alias, key string) []string {
-	return DefaultUserSettings.GetAll(alias, key)
+// AddConfigLocations adds a file to the list of ssh_config files to be searched when using Get, GetAll, GetStrict or
+// GetAllStrict. The list will be traversed from begin to end; the first file which holds the desired key will be used
+func (u *UserSettings) AddConfigLocations(finders ...ConfigFileFinder) *UserSettings {
+	u.configFiles = append(u.configFiles, finders...)
+	return u
 }
 
 // GetStrict finds the first value for key within a declaration that matches the
@@ -143,28 +100,36 @@ func GetAll(alias, key string) []string {
 // default will be returned. For more information on default values and the way
 // patterns are matched, see the manpage for ssh_config.
 //
-// The returned error will be non-nil if and only if a user's configuration file
-// or the system configuration file could not be parsed, and u.IgnoreErrors is
-// false.
-//
-// GetStrict is a wrapper around DefaultUserSettings.GetStrict.
-func GetStrict(alias, key string) (string, error) {
-	return DefaultUserSettings.GetStrict(alias, key)
-}
+// error will be non-nil if and only if a user's configuration file or the
+// system configuration file could not be parsed, and u.IgnoreErrors is false.
+func (u *UserSettings) doLoadConfigs() {
+	u.loadConfigs.Do(func() {
+		//use defaults if no ConfigFileFinder where set
+		if len(u.configFiles) == 0 {
+			u.configFiles = DefaultConfigFileFinders
+		}
 
-// GetAllStrict retrieves zero or more directives for key for the given alias.
-//
-// In most cases you want to use Get or GetStrict, which returns a single value.
-// However, a subset of ssh configuration values (IdentityFile, for example)
-// allow you to specify multiple directives.
-//
-// The returned error will be non-nil if and only if a user's configuration file
-// or the system configuration file could not be parsed, and u.IgnoreErrors is
-// false.
-//
-// GetAllStrict is a wrapper around DefaultUserSettings.GetAllStrict.
-func GetAllStrict(alias, key string) ([]string, error) {
-	return DefaultUserSettings.GetAllStrict(alias, key)
+		var location string
+		var err error
+
+		u.configs = make([]*Config, len(u.configFiles), len(u.configFiles))
+
+		for i := 0; i < len(u.configFiles); i++ {
+			location, err = u.configFiles[i]()
+			if err != nil {
+				u.onceErr = err
+				return
+			}
+
+			u.configs[i], err = parseFile(location)
+			// IsNotExist should be returned because a user specified this
+			// function - not existing likely means they made an error
+			if err != nil {
+				u.onceErr = err
+				return
+			}
+		}
+	})
 }
 
 // Get finds the first value for key within a declaration that matches the
@@ -172,7 +137,11 @@ func GetAllStrict(alias, key string) ([]string, error) {
 // is false and we could not parse the configuration file. Use GetStrict to
 // disambiguate the latter cases.
 //
-// The match for key is case insensitive.
+// All files specified using WithConfigLocations and AddConfigLocations are candidates for the searched alias, key
+// tuple. The list of available files will be traversed from begin to end.
+// The first file which holds the desired key will be used.
+//
+// The match for key is case-insensitive.
 func (u *UserSettings) Get(alias, key string) string {
 	val, err := u.GetStrict(alias, key)
 	if err != nil {
@@ -186,7 +155,11 @@ func (u *UserSettings) Get(alias, key string) string {
 // not parse the configuration file. Use GetStrict to disambiguate the latter
 // cases.
 //
-// The match for key is case insensitive.
+// All files specified using WithConfigLocations and AddConfigLocations are candidates for the searched alias, key
+// tuple. The list of available files will be traversed from begin to end.
+// The first file which holds the desired key will be used.
+//
+// The match for key is case-insensitive.
 func (u *UserSettings) GetAll(alias, key string) []string {
 	val, _ := u.GetAllStrict(alias, key)
 	return val
@@ -197,29 +170,27 @@ func (u *UserSettings) GetAll(alias, key string) []string {
 // default will be returned. For more information on default values and the way
 // patterns are matched, see the manpage for ssh_config.
 //
-// error will be non-nil if and only if a user's configuration file or the
-// system configuration file could not be parsed, and u.IgnoreErrors is false.
+// All files specified using WithConfigLocations and AddConfigLocations are candidates for the searched alias, key
+// tuple. The list of available files will be traversed from begin to end.
+// The first file which holds the desired key will be used.
+//
+// The returned error will be non-nil if and only if a user's configuration file
+// or the system configuration file could not be parsed, and u.IgnoreErrors is
+// false.
 func (u *UserSettings) GetStrict(alias, key string) (string, error) {
 	u.doLoadConfigs()
 	//lint:ignore S1002 I prefer it this way
 	if u.onceErr != nil && u.IgnoreErrors == false {
 		return "", u.onceErr
 	}
-	// TODO this is getting repetitive
-	if u.customConfig != nil {
-		val, err := findVal(u.customConfig, alias, key)
+
+	for _, c := range u.configs {
+		val, err := findVal(c, alias, key)
 		if err != nil || val != "" {
 			return val, err
 		}
 	}
-	val, err := findVal(u.userConfig, alias, key)
-	if err != nil || val != "" {
-		return val, err
-	}
-	val2, err2 := findVal(u.systemConfig, alias, key)
-	if err2 != nil || val2 != "" {
-		return val2, err2
-	}
+
 	return Default(key), nil
 }
 
@@ -228,6 +199,10 @@ func (u *UserSettings) GetStrict(alias, key string) (string, error) {
 // default will be returned. For more information on default values and the way
 // patterns are matched, see the manpage for ssh_config.
 //
+// All files specified using WithConfigLocations and AddConfigLocations are candidates for the searched alias, key
+// tuple. The list of available files will be traversed from begin to end.
+// The first file which holds the desired key will be used.
+//
 // The returned error will be non-nil if and only if a user's configuration file
 // or the system configuration file could not be parsed, and u.IgnoreErrors is
 // false.
@@ -237,20 +212,12 @@ func (u *UserSettings) GetAllStrict(alias, key string) ([]string, error) {
 	if u.onceErr != nil && u.IgnoreErrors == false {
 		return nil, u.onceErr
 	}
-	if u.customConfig != nil {
-		val, err := findAll(u.customConfig, alias, key)
+	for _, c := range u.configs {
+		val, err := findAll(c, alias, key)
 		if err != nil || val != nil {
 			return val, err
 		}
 	}
-	val, err := findAll(u.userConfig, alias, key)
-	if err != nil || val != nil {
-		return val, err
-	}
-	val2, err2 := findAll(u.systemConfig, alias, key)
-	if err2 != nil || val2 != nil {
-		return val2, err2
-	}
 	// TODO: IdentityFile has multiple default values that we should return.
 	if def := Default(key); def != "" {
 		return []string{def}, nil
@@ -258,56 +225,82 @@ func (u *UserSettings) GetAllStrict(alias, key string) ([]string, error) {
 	return []string{}, nil
 }
 
-// ConfigFinder will invoke f to try to find a ssh config file in a custom
-// location on disk, instead of in /etc/ssh or $HOME/.ssh. f should return the
-// name of a file containing SSH configuration.
-//
-// ConfigFinder must be invoked before any calls to Get or GetStrict and panics
-// if f is nil. Most users should not need to use this function.
-func (u *UserSettings) ConfigFinder(f func() string) {
-	if f == nil {
-		panic("cannot call ConfigFinder with nil function")
+func findVal(c *Config, alias, key string) (string, error) {
+	if c == nil {
+		return "", nil
 	}
-	u.customConfigFinder = f
+	val, err := c.Get(alias, key)
+	if err != nil || val == "" {
+		return "", err
+	}
+	if err := validate(key, val); err != nil {
+		return "", err
+	}
+	return val, nil
 }
 
-func (u *UserSettings) doLoadConfigs() {
-	u.loadConfigs.Do(func() {
-		var filename string
-		var err error
-		if u.customConfigFinder != nil {
-			filename = u.customConfigFinder()
-			u.customConfig, err = parseFile(filename)
-			// IsNotExist should be returned because a user specified this
-			// function - not existing likely means they made an error
-			if err != nil {
-				u.onceErr = err
-			}
-			return
-		}
-		if u.userConfigFinder == nil {
-			filename = userConfigFinder()
-		} else {
-			filename = u.userConfigFinder()
-		}
-		u.userConfig, err = parseFile(filename)
-		//lint:ignore S1002 I prefer it this way
-		if err != nil && os.IsNotExist(err) == false {
-			u.onceErr = err
-			return
-		}
-		if u.systemConfigFinder == nil {
-			filename = systemConfigFinder()
-		} else {
-			filename = u.systemConfigFinder()
-		}
-		u.systemConfig, err = parseFile(filename)
-		//lint:ignore S1002 I prefer it this way
-		if err != nil && os.IsNotExist(err) == false {
-			u.onceErr = err
-			return
-		}
-	})
+func findAll(c *Config, alias, key string) ([]string, error) {
+	if c == nil {
+		return nil, nil
+	}
+	return c.GetAll(alias, key)
+}
+
+// Get finds the first value for key within a declaration that matches the
+// alias. Get returns the empty string if no value was found, or if IgnoreErrors
+// is false and we could not parse the configuration file. Use GetStrict to
+// disambiguate the latter cases.
+//
+// The match for key is case-insensitive.
+//
+// Get is a wrapper around DefaultUserSettings.Get.
+func Get(alias, key string) string {
+	return DefaultUserSettings.Get(alias, key)
+}
+
+// GetAll retrieves zero or more directives for key for the given alias. GetAll
+// returns nil if no value was found, or if IgnoreErrors is false and we could
+// not parse the configuration file. Use GetAllStrict to disambiguate the
+// latter cases.
+//
+// In most cases you want to use Get or GetStrict, which returns a single value.
+// However, a subset of ssh configuration values (IdentityFile, for example)
+// allow you to specify multiple directives.
+//
+// The match for key is case-insensitive.
+//
+// GetAll is a wrapper around DefaultUserSettings.GetAll.
+func GetAll(alias, key string) []string {
+	return DefaultUserSettings.GetAll(alias, key)
+}
+
+// GetStrict finds the first value for key within a declaration that matches the
+// alias. If key has a default value and no matching configuration is found, the
+// default will be returned. For more information on default values and the way
+// patterns are matched, see the manpage for ssh_config.
+//
+// The returned error will be non-nil if and only if a user's configuration file
+// or the system configuration file could not be parsed, and u.IgnoreErrors is
+// false.
+//
+// GetStrict is a wrapper around DefaultUserSettings.GetStrict.
+func GetStrict(alias, key string) (string, error) {
+	return DefaultUserSettings.GetStrict(alias, key)
+}
+
+// GetAllStrict retrieves zero or more directives for key for the given alias.
+//
+// In most cases you want to use Get or GetStrict, which returns a single value.
+// However, a subset of ssh configuration values (IdentityFile, for example)
+// allow you to specify multiple directives.
+//
+// The returned error will be non-nil if and only if a user's configuration file
+// or the system configuration file could not be parsed, and u.IgnoreErrors is
+// false.
+//
+// GetAllStrict is a wrapper around DefaultUserSettings.GetAllStrict.
+func GetAllStrict(alias, key string) ([]string, error) {
+	return DefaultUserSettings.GetAllStrict(alias, key)
 }
 
 func parseFile(filename string) (*Config, error) {
@@ -319,12 +312,9 @@ func parseWithDepth(filename string, depth uint8) (*Config, error) {
 	if err != nil {
 		return nil, err
 	}
-	return decodeBytes(b, isSystem(filename), depth)
-}
 
-func isSystem(filename string) bool {
-	// TODO: not sure this is the best way to detect a system repo
-	return strings.HasPrefix(filepath.Clean(filename), "/etc/ssh")
+	parent := filepath.Dir(filename)
+	return decodeBytes(b, parent, depth)
 }
 
 // Decode reads r into a Config, or returns an error if r could not be parsed as
@@ -334,16 +324,16 @@ func Decode(r io.Reader) (*Config, error) {
 	if err != nil {
 		return nil, err
 	}
-	return decodeBytes(b, false, 0)
+	return decodeBytes(b, "", 0)
 }
 
 // DecodeBytes reads b into a Config, or returns an error if r could not be
 // parsed as an SSH config file.
 func DecodeBytes(b []byte) (*Config, error) {
-	return decodeBytes(b, false, 0)
+	return decodeBytes(b, "", 0)
 }
 
-func decodeBytes(b []byte, system bool, depth uint8) (c *Config, err error) {
+func decodeBytes(b []byte, cwd string, depth uint8) (c *Config, err error) {
 	defer func() {
 		if r := recover(); r != nil {
 			if _, ok := r.(runtime.Error); ok {
@@ -357,7 +347,7 @@ func decodeBytes(b []byte, system bool, depth uint8) (c *Config, err error) {
 		}
 	}()
 
-	c = parseSSH(lexSSH(b), system, depth)
+	c = parseSSH(lexSSH(b), cwd, depth)
 	return c, err
 }
 
@@ -374,7 +364,7 @@ type Config struct {
 // contains key. Get returns the empty string if no value was found, or if the
 // Config contains an invalid conditional Include value.
 //
-// The match for key is case insensitive.
+// The match for key is case-insensitive.
 func (c *Config) Get(alias, key string) (string, error) {
 	lowerKey := strings.ToLower(key)
 	for _, host := range c.Hosts {
@@ -386,7 +376,7 @@ func (c *Config) Get(alias, key string) (string, error) {
 			case *Empty:
 				continue
 			case *KV:
-				// "keys are case insensitive" per the spec
+				// "keys are case-insensitive" per the spec
 				lkey := strings.ToLower(t.Key)
 				if lkey == "match" {
 					panic("can't handle Match directives")
@@ -421,7 +411,7 @@ func (c *Config) GetAll(alias, key string) ([]string, error) {
 			case *Empty:
 				continue
 			case *KV:
-				// "keys are case insensitive" per the spec
+				// "keys are case-insensitive" per the spec
 				lkey := strings.ToLower(t.Key)
 				if lkey == "match" {
 					panic("can't handle Match directives")
@@ -711,7 +701,7 @@ func removeDups(arr []string) []string {
 // Configuration files are parsed greedily (e.g. as soon as this function runs).
 // Any error encountered while parsing nested configuration files will be
 // returned.
-func NewInclude(directives []string, hasEquals bool, pos Position, comment string, system bool, depth uint8) (*Include, error) {
+func NewInclude(basePath string, directives []string, hasEquals bool, pos Position, comment string, depth uint8) (*Include, error) {
 	if depth > maxRecurseDepth {
 		return nil, ErrDepthExceeded
 	}
@@ -730,10 +720,8 @@ func NewInclude(directives []string, hasEquals bool, pos Position, comment strin
 		var path string
 		if filepath.IsAbs(directives[i]) {
 			path = directives[i]
-		} else if system {
-			path = filepath.Join("/etc/ssh", directives[i])
 		} else {
-			path = filepath.Join(homedir(), ".ssh", directives[i])
+			path = filepath.Join(basePath, directives[i])
 		}
 		theseMatches, err := filepath.Glob(path)
 		if err != nil {
diff --git a/config_linux.go b/config_linux.go
new file mode 100644
index 0000000..82cccaf
--- /dev/null
+++ b/config_linux.go
@@ -0,0 +1,10 @@
+package ssh_config
+
+import "path/filepath"
+
+// SystemConfigFileFinder return ~/etc/ssh/ssh_config on linux os,
+func SystemConfigFileFinder() (string, error) {
+	return filepath.Join("/", "etc", "ssh", "ssh_config"), nil
+}
+
+var DefaultConfigFileFinders = []ConfigFileFinder{UserHomeConfigFileFinder, SystemConfigFileFinder}
diff --git a/config_nonlinux.go b/config_nonlinux.go
new file mode 100644
index 0000000..8116a49
--- /dev/null
+++ b/config_nonlinux.go
@@ -0,0 +1,5 @@
+//go:build !linux
+
+package ssh_config
+
+var DefaultConfigFileFinders = []ConfigFileFinder{UserHomeConfigFileFinder}
diff --git a/config_test.go b/config_test.go
index 11b203d..a1af8b1 100644
--- a/config_test.go
+++ b/config_test.go
@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"log"
 	"os"
-	"path/filepath"
 	"strings"
 	"testing"
 )
@@ -26,327 +25,504 @@ var files = []string{
 
 func TestDecode(t *testing.T) {
 	for _, filename := range files {
-		data := loadFile(t, filename)
-		cfg, err := Decode(bytes.NewReader(data))
-		if err != nil {
-			t.Fatal(err)
-		}
-		out := cfg.String()
-		if out != string(data) {
-			t.Errorf("%s out != data: got:\n%s\nwant:\n%s\n", filename, out, string(data))
-		}
+		t.Run(filename, func(t *testing.T) {
+			data := loadFile(t, filename)
+			cfg, err := Decode(bytes.NewReader(data))
+			if err != nil {
+				t.Fatal(err)
+			}
+			out := cfg.String()
+			if out != string(data) {
+				t.Errorf("%s out != data: got:\n%s\nwant:\n%s\n", filename, out, string(data))
+			}
+		})
 	}
 }
 
-func testConfigFinder(filename string) func() string {
-	return func() string { return filename }
-}
-
 func nullConfigFinder() string {
 	return ""
 }
 
-func TestGet(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/config1"),
-	}
+func TestUserSettings(t *testing.T) {
 
-	val := us.Get("wap", "User")
-	if val != "root" {
-		t.Errorf("expected to find User root, got %q", val)
+	assertFileFinder := func(t *testing.T, target *UserSettings, idx int, expected string) {
+		file, _ := target.configFiles[idx]()
+		if file != expected {
+			t.Errorf("set configuration was not previously used finder function; idx: %d", idx)
+		}
 	}
-}
 
-func TestGetWithDefault(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/config1"),
-	}
+	finderFncA := func() (string, error) { return "expected_file_A", nil }
+	finderFncB := func() (string, error) { return "expected_file_B", nil }
+	finderFncC := func() (string, error) { return "expected_file_C", nil }
 
-	val, err := us.GetStrict("wap", "PasswordAuthentication")
-	if err != nil {
-		t.Fatalf("expected nil err, got %v", err)
-	}
-	if val != "yes" {
-		t.Errorf("expected to get PasswordAuthentication yes, got %q", val)
+	testConfigFinder := func(filename string) ConfigFileFinder {
+		return func() (string, error) { return filename, nil }
 	}
-}
 
-func TestGetAllWithDefault(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/config1"),
-	}
+	assert := func(t *testing.T, target *UserSettings, host, key, expect string) {
+		val, err := target.GetStrict(host, key)
+		if err != nil {
+			t.Fatal(err)
+		}
 
-	val, err := us.GetAllStrict("wap", "PasswordAuthentication")
-	if err != nil {
-		t.Fatalf("expected nil err, got %v", err)
-	}
-	if len(val) != 1 || val[0] != "yes" {
-		t.Errorf("expected to get PasswordAuthentication yes, got %q", val)
+		if val != expect {
+			t.Errorf("wrong port: got %q want %s", val, expect)
+		}
 	}
-}
 
-func TestGetIdentities(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/identities"),
+	asserter := func(target *UserSettings, host, key, expect string) func(t *testing.T) {
+		return func(t *testing.T) { assert(t, target, host, key, expect) }
 	}
 
-	val, err := us.GetAllStrict("hasidentity", "IdentityFile")
-	if err != nil {
-		t.Errorf("expected nil err, got %v", err)
-	}
-	if len(val) != 1 || val[0] != "file1" {
-		t.Errorf(`expected ["file1"], got %v`, val)
-	}
+	t.Run("WithConfigLocations", func(t *testing.T) {
 
-	val, err = us.GetAllStrict("has2identity", "IdentityFile")
-	if err != nil {
-		t.Errorf("expected nil err, got %v", err)
-	}
-	if len(val) != 2 || val[0] != "f1" || val[1] != "f2" {
-		t.Errorf(`expected [\"f1\", \"f2\"], got %v`, val)
-	}
+		obj := &UserSettings{}
 
-	val, err = us.GetAllStrict("randomhost", "IdentityFile")
-	if err != nil {
-		t.Errorf("expected nil err, got %v", err)
-	}
-	if len(val) != len(defaultProtocol2Identities) {
-		// TODO: return the right values here.
-		log.Printf("expected defaults, got %v", val)
-	} else {
-		for i, v := range defaultProtocol2Identities {
-			if val[i] != v {
-				t.Errorf("invalid %d in val, expected %s got %s", i, v, val[i])
+		configuredObject := obj.WithConfigLocations(finderFncA, finderFncB)
+
+		if configuredObject != obj {
+			t.Errorf("the same instance back, got %v", configuredObject)
+		}
+
+		if len(obj.configFiles) != 2 {
+			t.Errorf("number of set file finder function does not match; expected 2 got : %d", len(obj.configFiles))
+		}
+
+		assertFileFinder(t, obj, 0, "expected_file_A")
+		assertFileFinder(t, obj, 1, "expected_file_B")
+	})
+
+	t.Run("AddConfigLocations", func(t *testing.T) {
+
+		obj := &UserSettings{configFiles: []ConfigFileFinder{finderFncA}}
+
+		if len(obj.configFiles) != 1 {
+			t.Errorf("number of set file finder function does not match; expected 1 got : %d", len(obj.configFiles))
+		}
+
+		configuredObject := obj.AddConfigLocations(finderFncB, finderFncC)
+
+		if configuredObject != obj {
+			t.Errorf("the same instance back, got %v", configuredObject)
+		}
+		if len(obj.configFiles) != 3 {
+			t.Errorf("number of set file finder function does not match; expected 1 got : %d", len(obj.configFiles))
+		}
+
+		assertFileFinder(t, obj, 0, "expected_file_A")
+		assertFileFinder(t, obj, 1, "expected_file_B")
+		assertFileFinder(t, obj, 2, "expected_file_C")
+	})
+
+	t.Run("Get", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/config1")},
+		}
+
+		val := us.Get("wap", "User")
+		if val != "root" {
+			t.Errorf("expected to find User root, got %q", val)
+		}
+	})
+
+	t.Run("GetWithDefault", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/config1")},
+		}
+
+		val, err := us.GetStrict("wap", "PasswordAuthentication")
+		if err != nil {
+			t.Fatalf("expected nil err, got %v", err)
+		}
+		if val != "yes" {
+			t.Errorf("expected to get PasswordAuthentication yes, got %q", val)
+		}
+	})
+
+	t.Run("GetAllWithDefault", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/config1")},
+		}
+
+		val, err := us.GetAllStrict("wap", "PasswordAuthentication")
+		if err != nil {
+			t.Fatalf("expected nil err, got %v", err)
+		}
+		if len(val) != 1 || val[0] != "yes" {
+			t.Errorf("expected to get PasswordAuthentication yes, got %q", val)
+		}
+	})
+
+	t.Run("GetIdentities", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/identities")},
+		}
+
+		val, err := us.GetAllStrict("hasidentity", "IdentityFile")
+		if err != nil {
+			t.Errorf("expected nil err, got %v", err)
+		}
+		if len(val) != 1 || val[0] != "file1" {
+			t.Errorf(`expected ["file1"], got %v`, val)
+		}
+
+		val, err = us.GetAllStrict("has2identity", "IdentityFile")
+		if err != nil {
+			t.Errorf("expected nil err, got %v", err)
+		}
+		if len(val) != 2 || val[0] != "f1" || val[1] != "f2" {
+			t.Errorf(`expected [\"f1\", \"f2\"], got %v`, val)
+		}
+
+		val, err = us.GetAllStrict("randomhost", "IdentityFile")
+		if err != nil {
+			t.Errorf("expected nil err, got %v", err)
+		}
+		if len(val) != len(defaultProtocol2Identities) {
+			// TODO: return the right values here.
+			log.Printf("expected defaults, got %v", val)
+		} else {
+			for i, v := range defaultProtocol2Identities {
+				if val[i] != v {
+					t.Errorf("invalid %d in val, expected %s got %s", i, v, val[i])
+				}
 			}
 		}
-	}
 
-	val, err = us.GetAllStrict("protocol1", "IdentityFile")
-	if err != nil {
-		t.Errorf("expected nil err, got %v", err)
-	}
-	if len(val) != 1 || val[0] != "~/.ssh/identity" {
-		t.Errorf("expected [\"~/.ssh/identity\"], got %v", val)
-	}
-}
+		val, err = us.GetAllStrict("protocol1", "IdentityFile")
+		if err != nil {
+			t.Errorf("expected nil err, got %v", err)
+		}
+		if len(val) != 1 || val[0] != "~/.ssh/identity" {
+			t.Errorf("expected [\"~/.ssh/identity\"], got %v", val)
+		}
+	})
 
-func TestGetInvalidPort(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/invalid-port"),
-	}
+	t.Run("GetInvalidPort", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/invalid-port")},
+		}
 
-	val, err := us.GetStrict("test.test", "Port")
-	if err == nil {
-		t.Fatalf("expected non-nil err, got nil")
-	}
-	if val != "" {
-		t.Errorf("expected to get '' for val, got %q", val)
-	}
-	if err.Error() != `ssh_config: strconv.ParseUint: parsing "notanumber": invalid syntax` {
-		t.Errorf("wrong error: got %v", err)
-	}
-}
+		val, err := us.GetStrict("test.test", "Port")
+		if err == nil {
+			t.Fatalf("expected non-nil err, got nil")
+		}
+		if val != "" {
+			t.Errorf("expected to get '' for val, got %q", val)
+		}
+		if err.Error() != `ssh_config: strconv.ParseUint: parsing "notanumber": invalid syntax` {
+			t.Errorf("wrong error: got %v", err)
+		}
+	})
 
-func TestGetNotFoundNoDefault(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/config1"),
-	}
+	t.Run("GetNotFoundNoDefault", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/config1")},
+		}
 
-	val, err := us.GetStrict("wap", "CanonicalDomains")
-	if err != nil {
-		t.Fatalf("expected nil err, got %v", err)
-	}
-	if val != "" {
-		t.Errorf("expected to get CanonicalDomains '', got %q", val)
-	}
-}
+		val, err := us.GetStrict("wap", "CanonicalDomains")
+		if err != nil {
+			t.Fatalf("expected nil err, got %v", err)
+		}
+		if val != "" {
+			t.Errorf("expected to get CanonicalDomains '', got %q", val)
+		}
+	})
 
-func TestGetAllNotFoundNoDefault(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/config1"),
-	}
+	t.Run("GetAllNotFoundNoDefault", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/config1")},
+		}
 
-	val, err := us.GetAllStrict("wap", "CanonicalDomains")
-	if err != nil {
-		t.Fatalf("expected nil err, got %v", err)
-	}
-	if len(val) != 0 {
-		t.Errorf("expected to get CanonicalDomains '', got %q", val)
-	}
-}
+		val, err := us.GetAllStrict("wap", "CanonicalDomains")
+		if err != nil {
+			t.Fatalf("expected nil err, got %v", err)
+		}
+		if len(val) != 0 {
+			t.Errorf("expected to get CanonicalDomains '', got %q", val)
+		}
+	})
 
-func TestGetWildcard(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/config3"),
-	}
+	t.Run("GetWildcard", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/config3")},
+		}
 
-	val := us.Get("bastion.stage.i.us.example.net", "Port")
-	if val != "22" {
-		t.Errorf("expected to find Port 22, got %q", val)
-	}
+		val := us.Get("bastion.stage.i.us.example.net", "Port")
+		if val != "22" {
+			t.Errorf("expected to find Port 22, got %q", val)
+		}
 
-	val = us.Get("bastion.net", "Port")
-	if val != "25" {
-		t.Errorf("expected to find Port 24, got %q", val)
-	}
+		val = us.Get("bastion.net", "Port")
+		if val != "25" {
+			t.Errorf("expected to find Port 24, got %q", val)
+		}
 
-	val = us.Get("10.2.3.4", "Port")
-	if val != "23" {
-		t.Errorf("expected to find Port 23, got %q", val)
-	}
-	val = us.Get("101.2.3.4", "Port")
-	if val != "25" {
-		t.Errorf("expected to find Port 24, got %q", val)
-	}
-	val = us.Get("20.20.20.4", "Port")
-	if val != "24" {
-		t.Errorf("expected to find Port 24, got %q", val)
-	}
-	val = us.Get("20.20.20.20", "Port")
-	if val != "25" {
-		t.Errorf("expected to find Port 25, got %q", val)
-	}
-}
+		val = us.Get("10.2.3.4", "Port")
+		if val != "23" {
+			t.Errorf("expected to find Port 23, got %q", val)
+		}
+		val = us.Get("101.2.3.4", "Port")
+		if val != "25" {
+			t.Errorf("expected to find Port 24, got %q", val)
+		}
+		val = us.Get("20.20.20.4", "Port")
+		if val != "24" {
+			t.Errorf("expected to find Port 24, got %q", val)
+		}
+		val = us.Get("20.20.20.20", "Port")
+		if val != "25" {
+			t.Errorf("expected to find Port 25, got %q", val)
+		}
+	})
 
-func TestGetExtraSpaces(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/extraspace"),
-	}
+	t.Run("GetExtraSpaces", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/extraspace")},
+		}
 
-	val := us.Get("test.test", "Port")
-	if val != "1234" {
-		t.Errorf("expected to find Port 1234, got %q", val)
-	}
-}
+		val := us.Get("test.test", "Port")
+		if val != "1234" {
+			t.Errorf("expected to find Port 1234, got %q", val)
+		}
+	})
 
-func TestGetCaseInsensitive(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/config1"),
-	}
+	t.Run("GetCaseInsensitive", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/config1")},
+		}
 
-	val := us.Get("wap", "uSER")
-	if val != "root" {
-		t.Errorf("expected to find User root, got %q", val)
-	}
-}
+		val := us.Get("wap", "uSER")
+		if val != "root" {
+			t.Errorf("expected to find User root, got %q", val)
+		}
+	})
 
-func TestGetEmpty(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder:   nullConfigFinder,
-		systemConfigFinder: nullConfigFinder,
-	}
-	val, err := us.GetStrict("wap", "User")
-	if err != nil {
-		t.Errorf("expected nil error, got %v", err)
-	}
-	if val != "" {
-		t.Errorf("expected to get empty string, got %q", val)
-	}
-}
+	t.Run("GetEmpty", func(t *testing.T) {
+		us := &UserSettings{}
 
-func TestGetEqsign(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/eqsign"),
-	}
+		val, err := us.GetStrict("wap", "User")
+		if err != nil {
+			t.Errorf("expected nil error, got %v", err)
+		}
+		if val != "" {
+			t.Errorf("expected to get empty string, got %q", val)
+		}
+	})
 
-	val := us.Get("test.test", "Port")
-	if val != "1234" {
-		t.Errorf("expected to find Port 1234, got %q", val)
-	}
-	val = us.Get("test.test", "Port2")
-	if val != "5678" {
-		t.Errorf("expected to find Port2 5678, got %q", val)
-	}
-}
+	t.Run("GetEqsign", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/eqsign")},
+		}
 
-var includeFile = []byte(`
-# This host should not exist, so we can use it for test purposes / it won't
-# interfere with any other configurations.
-Host kevinburke.ssh_config.test.example.com
-    Port 4567
-`)
+		val := us.Get("test.test", "Port")
+		if val != "1234" {
+			t.Errorf("expected to find Port 1234, got %q", val)
+		}
+		val = us.Get("test.test", "Port2")
+		if val != "5678" {
+			t.Errorf("expected to find Port2 5678, got %q", val)
+		}
+	})
 
-func TestInclude(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping fs write in short mode")
-	}
-	testPath := filepath.Join(homedir(), ".ssh", "kevinburke-ssh-config-test-file")
-	err := os.WriteFile(testPath, includeFile, 0644)
-	if err != nil {
-		t.Skipf("couldn't write SSH config file: %v", err.Error())
-	}
-	defer os.Remove(testPath)
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/include"),
-	}
-	val := us.Get("kevinburke.ssh_config.test.example.com", "Port")
-	if val != "4567" {
-		t.Errorf("expected to find Port=4567 in included file, got %q", val)
-	}
-}
+	t.Run("MatchUnsupported", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/match-directive")},
+		}
 
-func TestIncludeSystem(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping fs write in short mode")
-	}
-	testPath := filepath.Join("/", "etc", "ssh", "kevinburke-ssh-config-test-file")
-	err := os.WriteFile(testPath, includeFile, 0644)
-	if err != nil {
-		t.Skipf("couldn't write SSH config file: %v", err.Error())
-	}
-	defer os.Remove(testPath)
-	us := &UserSettings{
-		systemConfigFinder: testConfigFinder("testdata/include"),
-	}
-	val := us.Get("kevinburke.ssh_config.test.example.com", "Port")
-	if val != "4567" {
-		t.Errorf("expected to find Port=4567 in included file, got %q", val)
-	}
-}
+		_, err := us.GetStrict("test.test", "Port")
+		if err == nil {
+			t.Fatal("expected Match directive to error, didn't")
+		}
+		if !strings.Contains(err.Error(), "ssh_config: Match directive parsing is unsupported") {
+			t.Errorf("wrong error: %v", err)
+		}
+	})
 
-var recursiveIncludeFile = []byte(`
-Host kevinburke.ssh_config.test.example.com
-	Include kevinburke-ssh-config-recursive-include
-`)
+	t.Run("IndexInRange", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/config4")},
+		}
 
-func TestIncludeRecursive(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping fs write in short mode")
-	}
-	testPath := filepath.Join(homedir(), ".ssh", "kevinburke-ssh-config-recursive-include")
-	err := os.WriteFile(testPath, recursiveIncludeFile, 0644)
-	if err != nil {
-		t.Skipf("couldn't write SSH config file: %v", err.Error())
-	}
-	defer os.Remove(testPath)
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/include-recursive"),
-	}
-	val, err := us.GetStrict("kevinburke.ssh_config.test.example.com", "Port")
-	if err != ErrDepthExceeded {
-		t.Errorf("Recursive include: expected ErrDepthExceeded, got %v", err)
-	}
-	if val != "" {
-		t.Errorf("non-empty string value %s", val)
-	}
+		user, err := us.GetStrict("wap", "User")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if user != "root" {
+			t.Errorf("expected User to be %q, got %q", "root", user)
+		}
+	})
+
+	t.Run("DosLinesEndingsDecode", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/dos-lines")},
+		}
+
+		user, err := us.GetStrict("wap", "User")
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if user != "root" {
+			t.Errorf("expected User to be %q, got %q", "root", user)
+		}
+
+		host, err := us.GetStrict("wap2", "HostName")
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if host != "8.8.8.8" {
+			t.Errorf("expected HostName to be %q, got %q", "8.8.8.8", host)
+		}
+	})
+
+	t.Run("NoTrailingNewline", func(t *testing.T) {
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/config-no-ending-newline")},
+		}
+
+		port, err := us.GetStrict("example", "Port")
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if port != "4242" {
+			t.Errorf("wrong port: got %q want 4242", port)
+		}
+	})
+
+	t.Run("fallback resolving", func(t *testing.T) {
+
+		finderUser := testConfigFinder("testdata/test_config_fallback_user")
+		finderLayer2 := testConfigFinder("testdata/test_config_fallback_layer2")
+		finderLayer1 := testConfigFinder("testdata/test_config_fallback_layer1")
+		finderBase := testConfigFinder("testdata/test_config_fallback_base")
+
+		t.Run("user", func(t *testing.T) {
+			us := &UserSettings{
+				configFiles: []ConfigFileFinder{finderUser, finderLayer2, finderLayer1, finderBase},
+			}
+
+			t.Run("port custom", asserter(us, "custom", "Port", "2300"))
+			t.Run("port any", asserter(us, "some-host", "Port", "23"))
+			t.Run("user custom", asserter(us, "custom", "User", "pete"))
+			t.Run("user any", asserter(us, "some-host", "User", "foo"))
+		})
+
+		t.Run("layer2", func(t *testing.T) {
+			us := &UserSettings{
+				configFiles: []ConfigFileFinder{finderLayer2, finderLayer1, finderBase},
+			}
+
+			t.Run("port custom", asserter(us, "custom", "Port", "2300"))
+			t.Run("port any", asserter(us, "some-host", "Port", "23"))
+			t.Run("user custom", asserter(us, "custom", "User", "root"))
+			t.Run("user any", asserter(us, "some-host", "User", "foo"))
+		})
+
+		t.Run("layer1", func(t *testing.T) {
+			us := &UserSettings{
+				configFiles: []ConfigFileFinder{finderLayer1, finderBase},
+			}
+
+			t.Run("port custom", asserter(us, "custom", "Port", "23"))
+			t.Run("port any", asserter(us, "some-host", "Port", "23"))
+			t.Run("user custom", asserter(us, "custom", "User", "bar"))
+			t.Run("user any", asserter(us, "some-host", "User", "foo"))
+		})
+
+		t.Run("base", func(t *testing.T) {
+			us := &UserSettings{
+				configFiles: []ConfigFileFinder{finderBase},
+			}
+
+			t.Run("port custom", asserter(us, "custom", "Port", "22"))
+			t.Run("port any", asserter(us, "some-host", "Port", "22"))
+			t.Run("user custom", asserter(us, "custom", "User", "foo"))
+			t.Run("user any", asserter(us, "some-host", "User", "foo"))
+		})
+	})
+
+	t.Run("Include basic", func(t *testing.T) {
+
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/include-basic/config")},
+		}
+
+		assert(t, us, "kevinburke.ssh_config.test.example.com", "Port", "4567")
+		assert(t, us, "kevinburke.ssh_config.test.example.com", "User", "foobar")
+	})
+
+	t.Run("Include recursive", func(t *testing.T) {
+
+		us := &UserSettings{
+			configFiles: []ConfigFileFinder{testConfigFinder("testdata/include-recursive/config")},
+		}
+
+		val, err := us.GetStrict("kevinburke.ssh_config.test.example.com", "Port")
+		if err != ErrDepthExceeded {
+			t.Errorf("Recursive include: expected ErrDepthExceeded, got %v", err)
+		}
+		if val != "" {
+			t.Errorf("non-empty string value %s", val)
+		}
+	})
+
+	t.Run("IncludeString", func(t *testing.T) {
+		data, err := os.ReadFile("testdata/include-basic/config")
+		if err != nil {
+			log.Fatal(err)
+		}
+		c, err := Decode(bytes.NewReader(data))
+		if err != nil {
+			t.Fatal(err)
+		}
+		s := c.String()
+		if s != string(data) {
+			t.Errorf("mismatch: got %q\nwant %q", s, string(data))
+		}
+	})
 }
 
-func TestIncludeString(t *testing.T) {
-	if testing.Short() {
-		t.Skip("skipping fs write in short mode")
-	}
-	data, err := os.ReadFile("testdata/include")
+//TODO: this is not the way to to this!!!
+//
+//func TestIncludeSystem(t *testing.T) {
+//	if testing.Short() {
+//		t.Skip("skipping fs write in short mode")
+//	}
+//	testPath := filepath.Join("/", "etc", "ssh", "kevinburke-ssh-config-test-file")
+//	err := os.WriteFile(testPath, includeFile, 0644)
+//	if err != nil {
+//		t.Skipf("couldn't write SSH config file: %v", err.Error())
+//	}
+//	defer os.Remove(testPath)
+//	us := &UserSettings{
+//		systemConfigFinder: testConfigFinder("testdata/include"),
+//	}
+//	val := us.Get("kevinburke.ssh_config.test.example.com", "Port")
+//	if val != "4567" {
+//		t.Errorf("expected to find Port=4567 in included file, got %q", val)
+//	}
+//}
+
+func TestUserHomeConfigFileFinder(t *testing.T) {
+
+	userHome, err := UserHomeConfigFileFinder()
+
 	if err != nil {
-		log.Fatal(err)
+		t.Fatalf("no error expected; got %v", err)
 	}
-	c, err := Decode(bytes.NewReader(data))
-	if err != nil {
-		t.Fatal(err)
+
+	if userHome == "" {
+		t.Errorf("expected a return value; got %q", userHome)
 	}
-	s := c.String()
-	if s != string(data) {
-		t.Errorf("mismatch: got %q\nwant %q", s, string(data))
+
+	if !strings.HasSuffix(userHome, "/.ssh/config") {
+		t.Errorf("expected return value to match default windows folders; got %q", userHome)
 	}
+
 }
 
 var matchTests = []struct {
@@ -387,83 +563,3 @@ func TestMatches(t *testing.T) {
 		}
 	}
 }
-
-func TestMatchUnsupported(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/match-directive"),
-	}
-
-	_, err := us.GetStrict("test.test", "Port")
-	if err == nil {
-		t.Fatal("expected Match directive to error, didn't")
-	}
-	if !strings.Contains(err.Error(), "ssh_config: Match directive parsing is unsupported") {
-		t.Errorf("wrong error: %v", err)
-	}
-}
-
-func TestIndexInRange(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/config4"),
-	}
-
-	user, err := us.GetStrict("wap", "User")
-	if err != nil {
-		t.Fatal(err)
-	}
-	if user != "root" {
-		t.Errorf("expected User to be %q, got %q", "root", user)
-	}
-}
-
-func TestDosLinesEndingsDecode(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder: testConfigFinder("testdata/dos-lines"),
-	}
-
-	user, err := us.GetStrict("wap", "User")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if user != "root" {
-		t.Errorf("expected User to be %q, got %q", "root", user)
-	}
-
-	host, err := us.GetStrict("wap2", "HostName")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if host != "8.8.8.8" {
-		t.Errorf("expected HostName to be %q, got %q", "8.8.8.8", host)
-	}
-}
-
-func TestNoTrailingNewline(t *testing.T) {
-	us := &UserSettings{
-		userConfigFinder:   testConfigFinder("testdata/config-no-ending-newline"),
-		systemConfigFinder: nullConfigFinder,
-	}
-
-	port, err := us.GetStrict("example", "Port")
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if port != "4242" {
-		t.Errorf("wrong port: got %q want 4242", port)
-	}
-}
-
-func TestCustomFinder(t *testing.T) {
-	us := &UserSettings{}
-	us.ConfigFinder(func() string {
-		return "testdata/config1"
-	})
-
-	val := us.Get("wap", "User")
-	if val != "root" {
-		t.Errorf("expected to find User root, got %q", val)
-	}
-}
diff --git a/example_test.go b/example_test.go
index a7c16d6..cb757dc 100644
--- a/example_test.go
+++ b/example_test.go
@@ -4,9 +4,8 @@ import (
 	"fmt"
 	"path/filepath"
 	"strings"
-
-	"github.com/kevinburke/ssh_config"
 )
+import "github.com/kevinburke/ssh_config"
 
 func ExampleHost_Matches() {
 	pat, _ := ssh_config.NewPattern("test.*.example.com")
@@ -48,11 +47,15 @@ func ExampleDefault() {
 	//
 }
 
-func ExampleUserSettings_ConfigFinder() {
+func ExampleConfigFileFinder() {
 	// This can be used to test SSH config parsing.
 	u := ssh_config.UserSettings{}
-	u.ConfigFinder(func() string {
-		return filepath.Join("testdata", "test_config")
+	u.WithConfigLocations(func() (string, error) {
+		return filepath.Join("testdata", "test_config"), nil
 	})
-	u.Get("example.com", "Host")
+
+	fmt.Println(u.Get("example.com", "HostName"))
+	// Output:
+	// wap.example.org
+	//
 }
diff --git a/parser.go b/parser.go
index 2b1e718..39379d5 100644
--- a/parser.go
+++ b/parser.go
@@ -12,10 +12,8 @@ type sshParser struct {
 	tokensBuffer  []token
 	currentTable  []string
 	seenTableKeys []string
-	// /etc/ssh parser or local parser - used to find the default for relative
-	// filepaths in the Include directive
-	system bool
-	depth  uint8
+	cwd           string
+	depth         uint8
 }
 
 type sshParserStateFn func() sshParserStateFn
@@ -138,7 +136,7 @@ func (p *sshParser) parseKV() sshParserStateFn {
 	}
 	lastHost := p.config.Hosts[len(p.config.Hosts)-1]
 	if strings.ToLower(key.val) == "include" {
-		inc, err := NewInclude(strings.Split(val.val, " "), hasEquals, key.Position, comment, p.system, p.depth+1)
+		inc, err := NewInclude(p.cwd, strings.Split(val.val, " "), hasEquals, key.Position, comment, p.depth+1)
 		if err == ErrDepthExceeded {
 			p.raiseError(val, err)
 			return nil
@@ -177,7 +175,7 @@ func (p *sshParser) parseComment() sshParserStateFn {
 	return p.parseStart
 }
 
-func parseSSH(flow chan token, system bool, depth uint8) *Config {
+func parseSSH(flow chan token, cwd string, depth uint8) *Config {
 	// Ensure we consume tokens to completion even if parser exits early
 	defer func() {
 		for range flow {
@@ -192,7 +190,7 @@ func parseSSH(flow chan token, system bool, depth uint8) *Config {
 		tokensBuffer:  make([]token, 0),
 		currentTable:  make([]string, 0),
 		seenTableKeys: make([]string, 0),
-		system:        system,
+		cwd:           cwd,
 		depth:         depth,
 	}
 	parser.run()
diff --git a/testdata/include b/testdata/include
deleted file mode 100644
index ee238dd..0000000
--- a/testdata/include
+++ /dev/null
@@ -1,4 +0,0 @@
-Host kevinburke.ssh_config.test.example.com
-    # This file (or files) needs to be found in ~/.ssh or /etc/ssh, depending on
-    # the test.
-    Include kevinburke-ssh-config-*-file
diff --git a/testdata/include-basic/config b/testdata/include-basic/config
new file mode 100644
index 0000000..11a757d
--- /dev/null
+++ b/testdata/include-basic/config
@@ -0,0 +1,2 @@
+Host kevinburke.ssh_config.test.example.com
+    Include kevinburke-ssh-config-*-file
diff --git a/testdata/include-basic/kevinburke-ssh-config-test-file b/testdata/include-basic/kevinburke-ssh-config-test-file
new file mode 100644
index 0000000..6c0eccd
--- /dev/null
+++ b/testdata/include-basic/kevinburke-ssh-config-test-file
@@ -0,0 +1,2 @@
+Host kevinburke.ssh_config.test.example.com
+    Port 4567
diff --git a/testdata/include-basic/kevinburke-ssh-config-test2-file b/testdata/include-basic/kevinburke-ssh-config-test2-file
new file mode 100644
index 0000000..530b2ce
--- /dev/null
+++ b/testdata/include-basic/kevinburke-ssh-config-test2-file
@@ -0,0 +1,2 @@
+Host kevinburke.ssh_config.test.example.com
+    User foobar
diff --git a/testdata/include-recursive b/testdata/include-recursive
deleted file mode 100644
index 8a3cd3d..0000000
--- a/testdata/include-recursive
+++ /dev/null
@@ -1,4 +0,0 @@
-Host kevinburke.ssh_config.test.example.com
-	# This file (or files) needs to be found in ~/.ssh or /etc/ssh, depending on
-	# the test. It should include itself.
-	Include kevinburke-ssh-config-recursive-include
diff --git a/testdata/include-recursive/config b/testdata/include-recursive/config
new file mode 100644
index 0000000..3a6e4bc
--- /dev/null
+++ b/testdata/include-recursive/config
@@ -0,0 +1,2 @@
+Host kevinburke.ssh_config.test.example.com
+	Include kevinburke-ssh-config-recursive-include
diff --git a/testdata/include-recursive/kevinburke-ssh-config-recursive-include b/testdata/include-recursive/kevinburke-ssh-config-recursive-include
new file mode 100644
index 0000000..f3cc756
--- /dev/null
+++ b/testdata/include-recursive/kevinburke-ssh-config-recursive-include
@@ -0,0 +1,2 @@
+Host kevinburke.ssh_config.test.example.com
+    Include kevinburke-ssh-config-recursive-include
diff --git a/testdata/test_config b/testdata/test_config
new file mode 100644
index 0000000..c52854b
--- /dev/null
+++ b/testdata/test_config
@@ -0,0 +1,3 @@
+Host example.com
+  HostName wap.example.org
+  User root
diff --git a/testdata/test_config_fallback_base b/testdata/test_config_fallback_base
new file mode 100644
index 0000000..9d5fb37
--- /dev/null
+++ b/testdata/test_config_fallback_base
@@ -0,0 +1,5 @@
+
+
+Host *
+  User foo
+  Port 22
diff --git a/testdata/test_config_fallback_layer1 b/testdata/test_config_fallback_layer1
new file mode 100644
index 0000000..a4dbddc
--- /dev/null
+++ b/testdata/test_config_fallback_layer1
@@ -0,0 +1,6 @@
+
+Host *
+  Port 23
+
+Host custom
+  User bar
diff --git a/testdata/test_config_fallback_layer2 b/testdata/test_config_fallback_layer2
new file mode 100644
index 0000000..58e5cad
--- /dev/null
+++ b/testdata/test_config_fallback_layer2
@@ -0,0 +1,4 @@
+
+Host custom
+  User root
+  Port 2300
\ No newline at end of file
diff --git a/testdata/test_config_fallback_user b/testdata/test_config_fallback_user
new file mode 100644
index 0000000..d3528b5
--- /dev/null
+++ b/testdata/test_config_fallback_user
@@ -0,0 +1,3 @@
+
+Host custom
+  User pete