3 files changed, 6 insertions, 1 deletions
diff --git a/src/extension/extension.h b/src/extension/extension.h
index 13cb409a8..16c814d26 100644
--- a/src/extension/extension.h
+++ b/src/extension/extension.h
@@ -18,11 +18,14 @@
 #include <fstream>
 #include <vector>
 #include <gtkmm/widget.h>
-#include <gtkmm/box.h>
 #include <gtkmm/table.h>
 #include <glibmm/ustring.h>
 #include "xml/repr.h"
 
+namespace Gtk {
+	class VBox;
+}
+
 /** The key that is used to identify that the I/O should be autodetected */
 #define SP_MODULE_KEY_AUTODETECT "autodetect"
 /** This is the key for the SVG input module */
diff --git a/src/extension/param/enum.cpp b/src/extension/param/enum.cpp
index ff77c1603..846bfcb12 100644
--- a/src/extension/param/enum.cpp
+++ b/src/extension/param/enum.cpp
@@ -27,6 +27,7 @@
 #include "sp-object.h"
 #include "enum.h"
 #include "preferences.h"
+#include <gtkmm/box.h>
 
 namespace Inkscape {
 namespace Extension {
diff --git a/src/extension/param/radiobutton.cpp b/src/extension/param/radiobutton.cpp
index 1b52bebe5..706d68e02 100644
--- a/src/extension/param/radiobutton.cpp
+++ b/src/extension/param/radiobutton.cpp
@@ -28,6 +28,7 @@
 #include "sp-object.h"
 
 #include "radiobutton.h"
+#include <gtkmm/box.h>
 
 /**
  * The root directory in the preferences database for extension