diff --git a/settings/hyprland.nix b/settings/hyprland.nix
index 4503c9e..8021bbd 100644
--- a/settings/hyprland.nix
+++ b/settings/hyprland.nix
@@ -432,6 +432,14 @@ in
               suppress_event = "fullscreen maximize",
             })
 
+            -- Dungeon Runners does the same. Faugus/umu gives non-Steam games
+            -- the same steam_app_default class, so the generic tile rule above
+            -- already catches it; this only stops the fullscreen requests.
+            hl.window_rule({
+              match = { class = "steam_app_default", title = "^Dungeon Runners$" },
+              suppress_event = "fullscreen maximize",
+            })
+
             -- Battle.net requests activation on its own while running, which
             -- steals focus. Drop those events.
             --