diff --git a/lib/roken/strsep.c b/lib/roken/strsep.c
index c350fd31d..4ee3785f1 100644
--- a/lib/roken/strsep.c
+++ b/lib/roken/strsep.c
@@ -48,7 +48,7 @@ RCSID("$Id$");
 #ifndef HAVE_STRSEP
 
 char *
-strsep(char **str, char *delim)
+strsep(char **str, const char *delim)
 {
     char *save = *str;
     if(*str == NULL)