diff --git a/source/r_edge.c b/source/r_edge.c
index 82128ee..517bf26 100644
--- a/source/r_edge.c
+++ b/source/r_edge.c
@@ -303,7 +303,7 @@ R_CleanupSpan
 ==============
 */
 void
-R_CleanupSpan ()
+R_CleanupSpan (void)
 {
 	surf_t     *surf;
 	int         iu;