diff --git a/widget/gtk/WidgetStyleCache.cpp b/widget/gtk/WidgetStyleCache.cpp
index 1e72e027eff9..f3bc9f5fe6b6 100644
--- a/widget/gtk/WidgetStyleCache.cpp
+++ b/widget/gtk/WidgetStyleCache.cpp
@@ -637,7 +637,7 @@ static void CreateHeaderBarButtons() {
   ButtonLayout buttonLayout[TOOLBAR_BUTTONS];
 
   size_t activeButtons =
-      GetGtkHeaderBarButtonLayout(MakeSpan(buttonLayout), nullptr);
+      GetGtkHeaderBarButtonLayout(mozilla::MakeSpan(buttonLayout), nullptr);
 
   if (IsToolbarButtonEnabled(buttonLayout, activeButtons,
                              MOZ_GTK_HEADER_BAR_BUTTON_MINIMIZE)) {