diff --git a/dix/devices.c b/dix/devices.c
index bdcca5aba..4b20655c6 100644
--- a/dix/devices.c
+++ b/dix/devices.c
@@ -529,6 +529,7 @@ CloseDevice(DeviceIntPtr dev)
 	xfree(dev->key->curKeySyms.map);
 	xfree(dev->key->modifierKeyMap);
 	xfree(dev->key);
+        dev->key = NULL;
     }
 
     if (dev->valuator) {