diff --git a/src/charset.c b/src/charset.c
index df86852..6ad8ae5 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -351,7 +351,7 @@
 		else
 		{
 		    transchar_hex(hexbuf, c);
-		    len += STRLEN(hexbuf);
+		    len += (int)STRLEN(hexbuf);
 		}
 	    }
 	    else