diff --git a/src/xterm.c b/src/xterm.c
index f8ea787e8df..3a7e31e7129 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -10644,7 +10644,7 @@ get_current_wm_state (struct frame *f,
   int rc, actual_format;
   Atom actual_type;
   unsigned char *tmp_data = NULL;
-  Atom *reply_data;
+  Atom *reply_data UNINIT;
 #endif
 
   *sticky = false;