diff --git a/src/locale/iconv.c b/src/locale/iconv.c
index d469856c..3c1f4dd2 100644
--- a/src/locale/iconv.c
+++ b/src/locale/iconv.c
@@ -539,6 +539,7 @@ size_t iconv(iconv_t cd, char **restrict in, size_t *restrict inb, char **restri
 			if (*outb < 1) goto toobig;
 			if (c<256 && c==legacy_map(tomap, c)) {
 			revout:
+				if (*outb < 1) goto toobig;
 				*(*out)++ = c;
 				*outb -= 1;
 				break;