diff --git a/src/connect.c b/src/connect.c
index da1bf443..01f74ccb 100644
--- a/src/connect.c
+++ b/src/connect.c
@@ -64,6 +64,10 @@
 #include <wspiapi.h>
 #endif
 
+#ifndef EINPROGRESS
+#define EINPROGRESS WSAEINPROGRESS
+#endif
+
 #else /* _WIN32 */
 
 #include <netdb.h>