diff --git a/asyncssh/config.py b/asyncssh/config.py
index 18ff3c8..a50888a 100644
--- a/asyncssh/config.py
+++ b/asyncssh/config.py
@@ -425,7 +425,7 @@ class SSHClientConfig(SSHConfig):
     """Settings from an OpenSSH client config file"""
 
     _conditionals = {'host', 'match'}
-    _no_split = {'remotecommand'}
+    _no_split = {'proxycommand', 'remotecommand'}
     _percent_expand = {'CertificateFile', 'IdentityAgent',
                        'IdentityFile', 'ProxyCommand', 'RemoteCommand'}
 
@@ -559,7 +559,7 @@ def _set_tokens(self) -> None:
         ('PKCS11Provider',                  SSHConfig._set_string),
         ('PreferredAuthentications',        SSHConfig._set_string),
         ('Port',                            SSHConfig._set_int),
-        ('ProxyCommand',                    SSHConfig._set_string_list),
+        ('ProxyCommand',                    SSHConfig._set_string),
         ('ProxyJump',                       SSHConfig._set_string),
         ('PubkeyAuthentication',            SSHConfig._set_bool),
         ('RekeyLimit',                      SSHConfig._set_rekey_limits),
diff --git a/asyncssh/connection.py b/asyncssh/connection.py
index 9c05c5e..517fce4 100644
--- a/asyncssh/connection.py
+++ b/asyncssh/connection.py
@@ -115,7 +115,7 @@
 from .misc import TermModesArg, TermSizeArg
 from .misc import async_context_manager, construct_disc_error
 from .misc import get_symbol_names, ip_address, map_handler_name
-from .misc import parse_byte_count, parse_time_interval
+from .misc import parse_byte_count, parse_time_interval, split_args
 
 from .packet import Boolean, Byte, NameList, String, UInt32, PacketDecodeError
 from .packet import SSHPacket, SSHPacketHandler, SSHPacketLogger
@@ -231,7 +231,7 @@ async def create_server(self, session_factory: TCPListenerFactory,
 _GlobalRequestResult = Tuple[int, SSHPacket]
 _KeyOrCertOptions = Mapping[str, object]
 _ListenerArg = Union[bool, SSHListener]
-_ProxyCommand = Optional[Sequence[str]]
+_ProxyCommand = Optional[Union[str, Sequence[str]]]
 _RequestPTY = Union[bool, str]
 
 _TCPServerHandlerFactory = Callable[[str, int], SSHSocketSessionFactory]
@@ -7144,11 +7144,13 @@ def prepare(self, config: SSHConfig, # type: ignore
         self.tunnel = tunnel if tunnel != () else config.get('ProxyJump')
         self.passphrase = passphrase
 
+        if proxy_command == ():
+            proxy_command = cast(Optional[str], config.get('ProxyCommand'))
+
         if isinstance(proxy_command, str):
-            proxy_command = shlex.split(proxy_command)
+            proxy_command = split_args(proxy_command)
 
-        self.proxy_command = proxy_command if proxy_command != () else \
-            cast(Sequence[str], config.get('ProxyCommand'))
+        self.proxy_command = proxy_command
 
         self.family = cast(int, family if family != () else
             config.get('AddressFamily', socket.AF_UNSPEC))
@@ -9224,7 +9226,7 @@ async def create_server(server_factory: _ServerFactory,
 async def get_server_host_key(
         host = '', port: DefTuple[int] = (), *,
         tunnel: DefTuple[_TunnelConnector] = (),
-        proxy_command: DefTuple[str] = (), family: DefTuple[int] = (),
+        proxy_command: DefTuple[_ProxyCommand] = (), family: DefTuple[int] = (),
         flags: int = 0, local_addr: DefTuple[HostPort] = (),
         sock: Optional[socket.socket] = None,
         client_version: DefTuple[BytesOrStr] = (),
@@ -9368,7 +9370,7 @@ def conn_factory() -> SSHClientConnection:
 async def get_server_auth_methods(
         host = '', port: DefTuple[int] = (), username: DefTuple[str] = (), *,
         tunnel: DefTuple[_TunnelConnector] = (),
-        proxy_command: DefTuple[str] = (), family: DefTuple[int] = (),
+        proxy_command: DefTuple[_ProxyCommand] = (), family: DefTuple[int] = (),
         flags: int = 0, local_addr: DefTuple[HostPort] = (),
         sock: Optional[socket.socket] = None,
         client_version: DefTuple[BytesOrStr] = (),
diff --git a/asyncssh/misc.py b/asyncssh/misc.py
index d3765f2..76b8b28 100644
--- a/asyncssh/misc.py
+++ b/asyncssh/misc.py
@@ -23,6 +23,7 @@
 import functools
 import ipaddress
 import re
+import shlex
 import socket
 import sys
 
@@ -269,6 +270,18 @@ def parse_time_interval(value: str) -> float:
     return _parse_units(value, _time_units, 'time interval')
 
 
+def split_args(command: str) -> Sequence[str]:
+    """Split a command string into a list of arguments"""
+
+    lex = shlex.shlex(command, posix=True)
+    lex.whitespace_split = True
+
+    if sys.platform == 'win32': # pragma: no cover
+        lex.escape = []
+
+    return list(lex)
+
+
 _ACM = TypeVar('_ACM', bound=AsyncContextManager, covariant=True)
 
 class _ACMWrapper(Generic[_ACM]):