diff --git a/ext/mysql/php_mysql.c b/ext/mysql/php_mysql.c
index 2b3dfe35eb7..1414d6e173b 100644
--- a/ext/mysql/php_mysql.c
+++ b/ext/mysql/php_mysql.c
@@ -33,6 +33,7 @@
 
 #ifdef PHP_WIN32
 #include <winsock.h>
+#define signal(a,b) NULL
 #else
 #include "build-defs.h"