diff --git a/pluma/pluma-window.c b/pluma/pluma-window.c
index 7e1cee4..5fa926b 100644
--- a/pluma/pluma-window.c
+++ b/pluma/pluma-window.c
@@ -1649,6 +1649,10 @@ create_menu_bar_and_toolbar (PlumaWindow *window,
 			    0);
 
 	window->priv->toolbar = gtk_ui_manager_get_widget (manager, "/ToolBar");
+#if GTK_CHECK_VERSION(3, 0, 0)
+	gtk_style_context_add_class (gtk_widget_get_style_context (window->priv->toolbar),
+		GTK_STYLE_CLASS_PRIMARY_TOOLBAR);
+#endif
 	gtk_box_pack_start (GTK_BOX (main_box),
 			    window->priv->toolbar,
 			    FALSE,