diff --git a/docs/reference/gdk/macos.md b/docs/reference/gdk/macos.md
index 1a0429be9d..05d1fbbbbe 100644
--- a/docs/reference/gdk/macos.md
+++ b/docs/reference/gdk/macos.md
@@ -33,7 +33,7 @@ calls to different backends, and error out on unsupported windowing systems:
   else
 #endif
 #ifdef GDK_WINDOWING_WAYLAND
-  if (GTK_IS_WAYLAND_DISPLAY (display))
+  if (GDK_IS_WAYLAND_DISPLAY (display))
     {
       // make Wayland-specific calls here
     }
diff --git a/docs/reference/gdk/wayland.md b/docs/reference/gdk/wayland.md
index 040e96a4e9..470b7bbcf9 100644
--- a/docs/reference/gdk/wayland.md
+++ b/docs/reference/gdk/wayland.md
@@ -23,7 +23,7 @@ calls to different backends, and error out on unsupported windowing systems:
 #endif
 
 #ifdef GDK_WINDOWING_WAYLAND
-  if (GTK_IS_WAYLAND_DISPLAY (display))
+  if (GDK_IS_WAYLAND_DISPLAY (display))
     {
       // make Wayland-specific calls here
     }
diff --git a/docs/reference/gdk/x11.md b/docs/reference/gdk/x11.md
index 6602e24b82..ee4f173d8c 100644
--- a/docs/reference/gdk/x11.md
+++ b/docs/reference/gdk/x11.md
@@ -29,7 +29,7 @@ calls to different backends, and error out on unsupported windowing systems:
   else
 #endif
 #ifdef GDK_WINDOWING_WAYLAND
-  if (GTK_IS_WAYLAND_DISPLAY (display))
+  if (GDK_IS_WAYLAND_DISPLAY (display))
     {
       // make Wayland-specific calls here
     }