diff --git a/Modules/readline.c b/Modules/readline.c
index 37baf8ca92a..1bb60a85674 100644
--- a/Modules/readline.c
+++ b/Modules/readline.c
@@ -376,7 +376,7 @@ static char *
 call_readline(prompt)
 	char *prompt;
 {
-	int n;
+	size_t n;
 	char *p, *q;
 	RETSIGTYPE (*old_inthandler)();
 	old_inthandler = signal(SIGINT, onintr);