diff --git a/src/network/slirp/debug.c b/src/network/slirp/debug.c
index 9e72773..eef2c7d 100644
--- a/src/network/slirp/debug.c
+++ b/src/network/slirp/debug.c
@@ -19,7 +19,9 @@ int dostats = 0;
 #endif
 int slirp_debug = 0;
 
+#ifndef _MSC_VER
 extern char *strerror _P((int));
+#endif
 
 /* Carry over one item from main.c so that the tty's restored. 
  * Only done when the tty being used is /dev/tty --RedWolf */