diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5d998d4..8a4a7d8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,11 @@
+3.0.1
+-----
+
+Fixed:
+
+* Windows support was broken in 3.0.0
+
+
 3.0.0
 -----
 
diff --git a/Rakefile b/Rakefile
index 7264a0c..bf773e6 100644
--- a/Rakefile
+++ b/Rakefile
@@ -29,6 +29,8 @@ namespace "ffi-compiler" do
     t.cflags << "-D_GNU_SOURCE=1" if RbConfig::CONFIG["host_os"].downcase =~ /mingw/
     t.cflags << "-arch x86_64 -arch i386" if t.platform.mac?
     t.ldflags << "-arch x86_64 -arch i386" if t.platform.mac?
+
+    t.add_define 'WINDOWS_OS' if FFI::Platform.windows?
   end
 end
 task :compile_ffi => ["ffi-compiler:default"]
diff --git a/ext/scrypt/Rakefile b/ext/scrypt/Rakefile
index 98c6b57..9fb5da0 100644
--- a/ext/scrypt/Rakefile
+++ b/ext/scrypt/Rakefile
@@ -7,4 +7,6 @@ FFI::Compiler::CompileTask.new('scrypt_ext') do |t|
   t.cflags << "-arch x86_64 -arch i386" if t.platform.mac?
   t.ldflags << "-arch x86_64 -arch i386" if t.platform.mac?
   t.export '../../lib/scrypt/scrypt_ext.rb'
+
+  t.add_define 'WINDOWS_OS' if FFI::Platform.windows?
 end
diff --git a/ext/scrypt/crypto_scrypt.c b/ext/scrypt/crypto_scrypt.c
index 492936c..d38d710 100644
--- a/ext/scrypt/crypto_scrypt.c
+++ b/ext/scrypt/crypto_scrypt.c
@@ -29,8 +29,12 @@
 /* #include "bsdtar_platform.h" */
 
 #include <sys/types.h>
-#include <sys/mman.h>
-
+#if !defined(WINDOWS_OS)
+ 	#include <sys/mman.h>
+ 	#ifndef HAVE_MMAP
+		#define HAVE_MMAP 1
+ 	#endif
+#endif
 #include <errno.h>
 #include <stdint.h>
 #include <stdlib.h>
diff --git a/lib/scrypt/version.rb b/lib/scrypt/version.rb
index be3e6da..a990297 100644
--- a/lib/scrypt/version.rb
+++ b/lib/scrypt/version.rb
@@ -1,3 +1,3 @@
 module SCrypt
-  VERSION = "3.0.0"
+  VERSION = "3.0.1"
 end
diff --git a/scrypt.gemspec b/scrypt.gemspec
index 6f58e7f..1f2c88a 100644
--- a/scrypt.gemspec
+++ b/scrypt.gemspec
@@ -19,7 +19,7 @@ Gem::Specification.new do |s|
     alternative functions such as PBKDF2 or bcrypt.
   EOF
 
-  s.add_dependency 'ffi-compiler', '>= 0.0.2'
+  s.add_dependency 'ffi-compiler', '>= 1.0.0'
   s.add_dependency 'rake'
   s.add_development_dependency "rspec"
   s.add_development_dependency "rdoc"