diff --git a/src/Platform.h b/src/Platform.h
index 770a351..f2c4982 100644
--- a/src/Platform.h
+++ b/src/Platform.h
@@ -1,5 +1,11 @@
 #pragma once
 
+#ifdef _WIN32
+// Prevent bogus definitions of error codes
+// that are incompatible with Winsock errors.
+#define _CRT_NO_POSIX_ERROR_CODES
+#endif
+
 #include <stdlib.h>
 #include <string.h>
 #include <stdint.h>
diff --git a/src/PlatformSockets.h b/src/PlatformSockets.h
index 89feb41..5e5dffc 100644
--- a/src/PlatformSockets.h
+++ b/src/PlatformSockets.h
@@ -13,33 +13,10 @@
 
 #define SHUT_RDWR SD_BOTH
 
-// errno.h will include incompatible definitions of these
-// values compared to what Winsock uses, so we must undef
-// them to ensure the correct value is used.
-
-#ifdef EWOULDBLOCK
-#undef EWOULDBLOCK
-#endif
 #define EWOULDBLOCK WSAEWOULDBLOCK
-
-#ifdef EAGAIN
-#undef EAGAIN
-#endif
 #define EAGAIN WSAEWOULDBLOCK
-
-#ifdef EINPROGRESS
-#undef EINPROGRESS
-#endif
 #define EINPROGRESS WSAEINPROGRESS
-
-#ifdef EINTR
-#undef EINTR
-#endif
 #define EINTR WSAEINTR
-
-#ifdef ETIMEDOUT
-#undef ETIMEDOUT
-#endif
 #define ETIMEDOUT WSAETIMEDOUT
 
 typedef int SOCK_RET;