diff --git a/src/backend/backend.c b/src/backend/backend.c
index 293a86b..a1fb282 100644
--- a/src/backend/backend.c
+++ b/src/backend/backend.c
@@ -383,6 +383,10 @@ void paint_all_new(session_t *ps, struct managed_win *t, bool ignore_damage) {
 				    ps->backend_data, IMAGE_PROPERTY_BORDER_WIDTH,
 				    w->win_image, &border_width);
 			}
+
+			ps->backend_data->ops->set_image_property(
+			    ps->backend_data, IMAGE_PROPERTY_CUSTOM_SHADER, w->win_image,
+			    w->fg_shader ? (void *)w->fg_shader->backend_shader : NULL);
 		}
 
 		if (w->opacity * MAX_ALPHA < 1) {
diff --git a/src/backend/backend.h b/src/backend/backend.h
index 62d0f87..ff60ae1 100644
--- a/src/backend/backend.h
+++ b/src/backend/backend.h
@@ -70,6 +70,9 @@ enum image_properties {
 	// Border width
 	// 1 int, default: 0
 	IMAGE_PROPERTY_BORDER_WIDTH,
+	// Custom shader for this window.
+	// 1 pointer to shader struct, default: NULL
+	IMAGE_PROPERTY_CUSTOM_SHADER,
 };
 
 enum image_operations {
diff --git a/src/backend/backend_common.c b/src/backend/backend_common.c
index 5bd75e2..165a9dd 100644
--- a/src/backend/backend_common.c
+++ b/src/backend/backend_common.c
@@ -452,6 +452,7 @@ bool default_set_image_property(backend_t *base attr_unused, enum image_properti
 	case IMAGE_PROPERTY_CORNER_RADIUS: tex->corner_radius = dargs[0]; break;
 	case IMAGE_PROPERTY_MAX_BRIGHTNESS: tex->max_brightness = dargs[0]; break;
 	case IMAGE_PROPERTY_BORDER_WIDTH: tex->border_width = *(int *)arg; break;
+	case IMAGE_PROPERTY_CUSTOM_SHADER: break;
 	}
 
 	return true;