diff --git a/bin/pax/ftree.c b/bin/pax/ftree.c
index f402c568ddfa..1fb06ac74c3a 100644
--- a/bin/pax/ftree.c
+++ b/bin/pax/ftree.c
@@ -219,7 +219,7 @@ ftree_sel(ARCHD *arcn)
  */
 
 void
-ftree_notsel()
+ftree_notsel(void)
 {
 	if (ftent != NULL)
 		(void)fts_set(ftsp, ftent, FTS_SKIP);