diff --git a/src/apprt/gtk.zig b/src/apprt/gtk.zig
index a722c8e09..69a9634b4 100644
--- a/src/apprt/gtk.zig
+++ b/src/apprt/gtk.zig
@@ -459,6 +459,16 @@ const Window = struct {
         }
     }
 
+    /// Toggle fullscreen for this window.
+    fn toggleFullscreen(self: *Window) void {
+        const is_fullscreen = c.gtk_window_is_fullscreen(self.window);
+        if (is_fullscreen == 0) {
+            c.gtk_window_fullscreen(self.window);
+        } else {
+            c.gtk_window_unfullscreen(self.window);
+        }
+    }
+
     /// Grabs focus on the currently selected tab.
     fn focusCurrentTab(self: *Window) void {
         const page_idx = c.gtk_notebook_get_current_page(self.notebook);
@@ -795,6 +805,10 @@ pub const Surface = struct {
         c.gtk_widget_show(alert);
     }
 
+    pub fn toggleFullscreen(self: *Surface) void {
+        self.window.toggleFullscreen();
+    }
+
     pub fn newTab(self: *Surface) !void {
         try self.window.newTab();
     }