diff --git a/gtk/gtktoolitemgroup.h b/gtk/gtktoolitemgroup.h
index 4a1b9b48c9..82f153ce2e 100644
--- a/gtk/gtktoolitemgroup.h
+++ b/gtk/gtktoolitemgroup.h
@@ -19,6 +19,10 @@
  *      Mathias Hasselmann
  */
 
+#if !defined (__GTK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gtk/gtk.h> can be included directly."
+#endif
+
 #ifndef __GTK_TOOL_ITEM_GROUP_H__
 #define __GTK_TOOL_ITEM_GROUP_H__
 
diff --git a/gtk/gtktoolpalette.h b/gtk/gtktoolpalette.h
index 36eb379dbc..e45b9a1dcf 100644
--- a/gtk/gtktoolpalette.h
+++ b/gtk/gtktoolpalette.h
@@ -19,6 +19,10 @@
  *      Mathias Hasselmann
  */
 
+#if !defined (__GTK_H_INSIDE__) && !defined (GTK_COMPILATION)
+#error "Only <gtk/gtk.h> can be included directly."
+#endif
+
 #ifndef __GTK_TOOL_PALETTE_H__
 #define __GTK_TOOL_PALETTE_H__