1 files changed, 1 insertions, 0 deletions
diff --git a/openbox/prop.c b/openbox/prop.c
index 695e441f..5dc4a2fa 100644
--- a/openbox/prop.c
+++ b/openbox/prop.c
@@ -51,6 +51,7 @@ void prop_startup(void)
     CREATE(wm_client_machine, "WM_CLIENT_MACHINE");
     CREATE(wm_command, "WM_COMMAND");
     CREATE(wm_client_leader, "WM_CLIENT_LEADER");
+    CREATE(wm_transient_for, "WM_TRANSIENT_FOR");
     CREATE(motif_wm_hints, "_MOTIF_WM_HINTS");
 
     CREATE(sm_client_id, "SM_CLIENT_ID");