diff --git a/src/d_netcmd.c b/src/d_netcmd.c
index 7a76002f..9fa5db78 100644
--- a/src/d_netcmd.c
+++ b/src/d_netcmd.c
@@ -1044,7 +1044,7 @@ static boolean AllowedPlayerNameChar(char ch)
 	return true;
 }
 
-boolean EnsurePlayerNameIsGood(char *name, INT32 playernum)
+static boolean EnsurePlayerNameIsGood(char *name, INT32 playernum)
 {
 	INT32 ix;