diff --git a/src/render.c b/src/render.c
index e7d599e..ac3320e 100644
--- a/src/render.c
+++ b/src/render.c
@@ -443,7 +443,7 @@ static void paint_root(session_t *ps, const region_t *reg_paint) {
 	             ps->root_tile_paint.pict);
 }
 
-static xcb_image_t *make_shadow(session_t *ps, double opacity, int width, int height) {
+xcb_image_t *make_shadow(session_t *ps, double opacity, int width, int height) {
 	xcb_image_t *ximage;
 	int ylimit, xlimit;
 	int swidth = width + ps->cgsize;
diff --git a/src/render.h b/src/render.h
index eca135e..e5fc25f 100644
--- a/src/render.h
+++ b/src/render.h
@@ -3,6 +3,7 @@
 #pragma once
 
 #include <xcb/render.h>
+#include <xcb/xcb_image.h>
 #include "region.h"
 
 typedef struct _glx_texture glx_texture_t;
@@ -34,3 +35,5 @@ void free_root_tile(session_t *ps);
 
 bool init_render(session_t *ps);
 void deinit_render(session_t *ps);
+
+xcb_image_t *make_shadow(session_t *ps, double opacity, int width, int height);