diff --git a/src/charset.c b/src/charset.c
index cff62e1..171eccb 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -355,10 +355,10 @@
 		    len += 4;	/* illegal byte sequence */
 	    }
 	}
-	res = alloc((unsigned)(len + 1));
+	res = alloc(len + 1);
     }
     else
-	res = alloc((unsigned)(vim_strsize(s) + 1));
+	res = alloc(vim_strsize(s) + 1);
     if (res != NULL)
     {
 	*res = NUL;