diff --git a/Xi/setbmap.c b/Xi/setbmap.c
index b6f62dddb..f29389d45 100644
--- a/Xi/setbmap.c
+++ b/Xi/setbmap.c
@@ -101,6 +101,10 @@ ProcXSetDeviceButtonMapping(ClientPtr client)
 			  stuff->map_length + 3) >> 2)
 	return BadLength;
 
+    ret = dixLookupDevice(&dev, stuff->deviceid, client, DixManageAccess);
+    if (ret != Success)
+        return ret;
+
     rep.repType = X_Reply;
     rep.RepType = X_SetDeviceButtonMapping;
     rep.length = 0;