diff --git a/src/tools/wininterrupt/wininterrupt.c b/src/tools/wininterrupt/wininterrupt.c
index 8053d6db3cc..47559a30fa7 100644
--- a/src/tools/wininterrupt/wininterrupt.c
+++ b/src/tools/wininterrupt/wininterrupt.c
@@ -11,6 +11,7 @@
 
 #include <windows.h>
 #include <stdio.h>
+#include <stdlib.h>
 
 /* To debug break a 64bit application under Windows, you must call
  * DebugBreakProcess() from an 64bit apllication. Therefore: