diff --git a/src/apprt/gtk/Surface.zig b/src/apprt/gtk/Surface.zig
index dce2517ab..ecf59a647 100644
--- a/src/apprt/gtk/Surface.zig
+++ b/src/apprt/gtk/Surface.zig
@@ -857,12 +857,9 @@ pub fn setInitialWindowSize(self: *const Surface, width: u32, height: u32) !void
         @intCast(height),
     );
 
-    // TODO: move this check somewhere else so we can reuse it
     // If the current WM doesn't support _NET_WM_STATE, we shouldn't try to set it.
     const gdk_surface = c.gtk_native_get_surface(@ptrCast(window.window));
-    if (c.g_type_check_instance_is_a(@ptrCast(@alignCast(gdk_surface)), c.gdk_x11_surface_get_type()) == 0) return; // X11 only, sorry Wayland
-
-    if (c.XInternAtom(c.gdk_x11_display_get_xdisplay(c.gdk_surface_get_display(gdk_surface)), "_NET_WM_STATE", 1) == 0) {
+    if (!x11.should_use_net_wm_state(gdk_surface)) {
         log.warn("current WM does not support _NET_WM_STATE", .{});
         return;
     }
diff --git a/src/apprt/gtk/Window.zig b/src/apprt/gtk/Window.zig
index e18e85c0e..cf56029ae 100644
--- a/src/apprt/gtk/Window.zig
+++ b/src/apprt/gtk/Window.zig
@@ -26,6 +26,7 @@ const Notebook = @import("notebook.zig").Notebook;
 const HeaderBar = @import("headerbar.zig").HeaderBar;
 const version = @import("version.zig");
 const wayland = @import("wayland.zig");
+const x11 = @import("x11.zig");
 
 const log = std.log.scoped(.gtk);
 
@@ -623,16 +624,13 @@ fn gtkWindowNotifyMaximized(
     _: ?*anyopaque,
 ) callconv(.C) void {
     const gdk_surface = c.gtk_native_get_surface(@ptrCast(window));
-    if (c.g_type_check_instance_is_a(@ptrCast(@alignCast(gdk_surface)), c.gdk_x11_surface_get_type()) == 0) return; // X11 only, sorry Wayland
-
-    const xdisplay = c.gdk_x11_display_get_xdisplay(c.gdk_surface_get_display(gdk_surface)) orelse return;
-
-    // If the WM doesn't support _NET_WM_STATE, no need to continue.
-    if (c.XInternAtom(xdisplay, "_NET_WM_STATE", 1) == 0) {
+    if (!x11.should_use_net_wm_state(gdk_surface)) {
         log.warn("current WM does not support _NET_WM_STATE", .{});
         return;
     }
 
+    const xdisplay = c.gdk_x11_display_get_xdisplay(c.gdk_surface_get_display(gdk_surface)) orelse return;
+
     // https://tronche.com/gui/x/xlib/events/client-communication/client-message.html#XClientMessageEvent
     var client_message_event: c.XClientMessageEvent = std.mem.zeroes(c.XClientMessageEvent);
     client_message_event.type = c.ClientMessage;
diff --git a/src/apprt/gtk/x11.zig b/src/apprt/gtk/x11.zig
index 21ff87b34..67b7b00ab 100644
--- a/src/apprt/gtk/x11.zig
+++ b/src/apprt/gtk/x11.zig
@@ -22,6 +22,17 @@ pub fn is_current_display_server() bool {
     return is_display(display);
 }
 
+/// Returns true if we have a valid X11 surface and the current WM supports _NET_WM_STATE.
+pub fn should_use_net_wm_state(surface: ?*c.GdkSurface) bool {
+    if (comptime !build_options.x11) return false;
+    if (c.g_type_check_instance_is_a(
+        @ptrCast(@alignCast(surface)),
+        c.gdk_x11_surface_get_type(),
+    ) == 0) return false;
+
+    return c.XInternAtom(c.gdk_x11_display_get_xdisplay(c.gdk_surface_get_display(surface)), "_NET_WM_STATE", 1) != 0;
+}
+
 pub const Xkb = struct {
     base_event_code: c_int,