Index: layer.h
===================================================================
--- layer.h	(revision 19668)
+++ layer.h	(revision 19669)
@@ -172,8 +172,8 @@
 } pcb_side_t;
 
 /* Cached lookup of the first silk layer in the bottom or top group */
-pcb_layer_id_t pcb_layer_get_bottom_silk();
-pcb_layer_id_t pcb_layer_get_top_silk();
+pcb_layer_id_t pcb_layer_get_bottom_silk(void);
+pcb_layer_id_t pcb_layer_get_top_silk(void);
 
 /* Return the board the layer is under */
 #define pcb_layer_get_top(layer) pcb_data_get_top((layer)->parent.data)