diff --git a/Modules/signalmodule.c b/Modules/signalmodule.c
index 251e67c..e9abec4 100644
--- a/Modules/signalmodule.c
+++ b/Modules/signalmodule.c
@@ -7,8 +7,11 @@
 #include "intrcheck.h"
 
 #ifdef MS_WINDOWS
+#include <Windows.h>
+#ifdef HAVE_PROCESS_H
 #include <process.h>
 #endif
+#endif
 
 #include <signal.h>