diff --git a/src/event_loop/handlers.rs b/src/event_loop/handlers.rs
index 3dca314..a3e5e84 100644
--- a/src/event_loop/handlers.rs
+++ b/src/event_loop/handlers.rs
@@ -19,7 +19,7 @@ use smithay_client_toolkit::
 		wlr_layer::{ LayerShellHandler, LayerSurface, LayerSurfaceConfigure },
 		xdg::XdgSurface,
 		xdg::popup::{ Popup, PopupConfigure, PopupHandler },
-		xdg::window::{ Window, WindowConfigure, WindowHandler },
+		xdg::window::{ DecorationMode, Window, WindowConfigure, WindowHandler },
 	},
 	shm::{ Shm, ShmHandler },
 	session_lock::{ SessionLock, SessionLockHandler, SessionLockSurface, SessionLockSurfaceConfigure },
@@ -222,6 +222,14 @@ impl<A: App> WindowHandler for AppData<A>
 			window.set_max_size( None );
 			self.pending_size_hint_unpin = false;
 		}
+		let tb = if configure.decoration_mode == DecorationMode::Server { 0.0 }
+			else { self.main.titlebar_base };
+		if self.main.titlebar_height != tb
+		{
+			self.main.titlebar_height = tb;
+			self.main.content_dirty   = true;
+			self.view_dirty           = true;
+		}
 		let ( hint_w, hint_h ) = self.app.window_size_hint().unwrap_or( ( 800, 600 ) );
 		let w = configure.new_size.0.map( |v| v.get() ).unwrap_or( hint_w );
 		let h = configure.new_size.1.map( |v| v.get() ).unwrap_or( hint_h );
diff --git a/src/event_loop/surface.rs b/src/event_loop/surface.rs
index 1e05c3b..0b41dbe 100644
--- a/src/event_loop/surface.rs
+++ b/src/event_loop/surface.rs
@@ -260,6 +260,9 @@ pub( crate ) struct SurfaceState<Msg: Clone>
 	pub touch_slots:        HashMap<i32, crate::types::Point>,
 	/// Height of the client-side title bar (0 for layer-shell surfaces).
 	pub titlebar_height:    f32,
+	/// Title bar height before decoration negotiation; restored when the
+	/// compositor hands decorations back to the client.
+	pub titlebar_base:      f32,
 	/// Title text shown in the client-side title bar.
 	pub titlebar_title:     String,
 	/// Rect of the close button in the title bar (for hit testing).
@@ -313,6 +316,7 @@ impl<Msg: Clone> SurfaceState<Msg>
 			context_menu:        None,
 			gesture:             GestureState::new(),
 			titlebar_height,
+			titlebar_base:       titlebar_height,
 			titlebar_title,
 			titlebar_close_rect: Rect::default(),
 			scale_factor:        1,