diff --git a/slirp/slirp.h b/slirp/slirp.h
index 2098b20..46bfe46 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -15,6 +15,12 @@
 # include <sys/timeb.h>
 # include <iphlpapi.h>
 
+# undef EWOULDBLOCK
+# undef EINPROGRESS
+# undef ENOTCONN
+# undef EHOSTUNREACH
+# undef ENETUNREACH
+# undef ECONNREFUSED
 # define EWOULDBLOCK WSAEWOULDBLOCK
 # define EINPROGRESS WSAEINPROGRESS
 # define ENOTCONN WSAENOTCONN