diff --git a/src/pc/gfx/gfx_glx.h b/src/pc/gfx/gfx_glx.h
index fe78db94..1ca41090 100644
--- a/src/pc/gfx/gfx_glx.h
+++ b/src/pc/gfx/gfx_glx.h
@@ -3,6 +3,6 @@
 
 #include "gfx_window_manager_api.h"
 
-struct GfxWindowManagerAPI gfx_glx;
+extern struct GfxWindowManagerAPI gfx_glx;
 
 #endif