diff --git a/src/backends/xlib/mod.rs b/src/backends/xlib/mod.rs
index b559a41..00bb14a 100644
--- a/src/backends/xlib/mod.rs
+++ b/src/backends/xlib/mod.rs
@@ -121,6 +121,7 @@ pub mod wmh {
         WmActiveWindow,
         WmTakeFocus,
         WmState,
+        WmTransientFor,
     }
 
     #[derive(Debug, Clone)]
@@ -183,6 +184,7 @@ pub mod wmh {
                 ICCCMAtom::WmActiveWindow => "WM_ACTIVE_WINDOW",
                 ICCCMAtom::WmTakeFocus => "WM_TAKE_FOCUS",
                 ICCCMAtom::WmState => "WM_STATE",
+                ICCCMAtom::WmTransientFor => "WM_TRANSIENT_FOR",
             }
         }
     }