diff --git a/Modules/_csv.c b/Modules/_csv.c
index 5e03635..a85126a 100644
--- a/Modules/_csv.c
+++ b/Modules/_csv.c
@@ -993,13 +993,10 @@ join_append_data(WriterObj *self, char *field, int quote_empty,
 		ADDCH(dialect->quotechar);
 
 	/* Copy/count field data */
-	for (i = 0;; i++) {
+	for (i = 0; i < strlen(field) ; i++) {
 		char c = field[i];
 		int want_escape = 0;
 
-		if (c == '\0')
-			break;
-
 		if (c == dialect->delimiter ||
 		    c == dialect->escapechar ||
 		    c == dialect->quotechar ||