diff --git a/Xi/xipassivegrab.c b/Xi/xipassivegrab.c
index 22f905e8f..5b4cc4610 100644
--- a/Xi/xipassivegrab.c
+++ b/Xi/xipassivegrab.c
@@ -159,6 +159,8 @@ ProcXIPassiveGrabDevice(ClientPtr client)
 	return status;
 
     status = CheckGrabValues(client, &param);
+    if (status != Success)
+        return status;
 
     modifiers = (uint32_t*)&stuff[1] + stuff->mask_len;
     modifiers_failed = calloc(stuff->num_modifiers, sizeof(xXIGrabModifierInfo));