--- a/panel/plugin.c
+++ b/panel/plugin.c
@@ -22,6 +22,7 @@
 /**************************************************************/
 static GHashTable *class_ht;
 
+struct _plugin_instance *stam;
 
 void
 class_register(plugin_class *p)
--- a/panel/plugin.h
+++ b/panel/plugin.h
@@ -9,7 +9,7 @@
 #include <stdio.h>
 #include "panel.h"
 
-struct _plugin_instance *stam;
+extern struct _plugin_instance *stam;
 
 typedef struct {
     /* common */