diff --git a/src/mainwin.h b/src/mainwin.h
index ee32a7d..5f0a39b 100644
--- a/src/mainwin.h
+++ b/src/mainwin.h
@@ -1,7 +1,7 @@
 #ifndef __MAINWIN_H__
 #define __MAINWIN_H__
 
-cairo_surface_t * pixsurf;
+extern cairo_surface_t * pixsurf;
 
 void mw_create(gint da_width, gint da_height);
 void mw_small_balls_add(GtkWidget *child);