diff --git a/lib/roken/warnerr.c b/lib/roken/warnerr.c
index 1fde0cb32..37f6fa6c8 100644
--- a/lib/roken/warnerr.c
+++ b/lib/roken/warnerr.c
@@ -61,7 +61,7 @@ setprogname(const char *argv0)
 	return;
     p = strrchr(argv0, '/');
     if(p == NULL)
-	p = argv0;
+	p = (char *)argv0;
     else
 	p++;
     __progname = p;