Index: src_plugins/hid_gtk3_cairo/gtkhid-cairo.c
===================================================================
--- src_plugins/hid_gtk3_cairo/gtkhid-cairo.c	(revision 10438)
+++ src_plugins/hid_gtk3_cairo/gtkhid-cairo.c	(revision 10439)
@@ -106,7 +106,7 @@
 */
 
 /** Duplicates the source fields to destination. */
-static copy_color(GdkRGBA * dest, GdkRGBA * source)
+static void copy_color(GdkRGBA * dest, GdkRGBA * source)
 {
 	dest->red = source->red;
 	dest->green = source->green;