diff --git a/reactos/win32ss/user/user32/misc/stubs.c b/reactos/win32ss/user/user32/misc/stubs.c
index 61f0fa26dbf..aa7e75e7601 100644
--- a/reactos/win32ss/user/user32/misc/stubs.c
+++ b/reactos/win32ss/user/user32/misc/stubs.c
@@ -335,7 +335,8 @@ GetRawInputDeviceList(
 {
     if(pRawInputDeviceList)
         memset(pRawInputDeviceList, 0, sizeof *pRawInputDeviceList);
-    *puiNumDevices = 0;
+    if(puiNumDevices)
+       *puiNumDevices = 0;
 
     UNIMPLEMENTED;
     return 0;