diff --git a/include/X11/extensions/XRes.h b/include/X11/extensions/XRes.h
index 1c816165e..8da68aa23 100644
--- a/include/X11/extensions/XRes.h
+++ b/include/X11/extensions/XRes.h
@@ -6,7 +6,10 @@
 #define _XRES_H
 
 #include <X11/Xfuncproto.h>
-
+#if defined(_MSC_VER)
+    #include <process.h>
+    typedef int pid_t;
+#endif
 /* v1.0 */
 
 typedef struct {