--- a/src/ml_gdk.c
+++ b/src/ml_gdk.c
@@ -55,6 +55,8 @@
 #define GDK_WINDOW_TYPE_HINT_DOCK GDK_WINDOW_TYPE_HINT_NORMAL
 #endif
 
+lookup_info *ml_table_extension_events;
+
 CAMLprim void ml_raise_gdk (const char *errmsg)
 {
   static const value * exn = NULL;
--- a/src/ml_gdk.h
+++ b/src/ml_gdk.h
@@ -102,7 +102,7 @@ CAMLexport value Val_GdkEvent (GdkEvent
 CAMLexport int OptFlags_GdkModifier_val (value);
 CAMLexport int Flags_GdkModifier_val (value);
 CAMLexport int Flags_Event_mask_val (value);
-CAMLexport lookup_info *ml_table_extension_events;
+CAMLextern lookup_info *ml_table_extension_events;
 #define Extension_events_val(key) ml_lookup_to_c(ml_table_extension_events,key)
 
 #define GdkDragContext_val(val) check_cast(GDK_DRAG_CONTEXT,val)