diff --git a/ext/posix/posix.c b/ext/posix/posix.c
index e5ab4b5940a5..dbc888a7ea69 100644
--- a/ext/posix/posix.c
+++ b/ext/posix/posix.c
@@ -952,7 +952,7 @@ PHP_FUNCTION(posix_getpwuid)
 try_again:
 	err = getpwuid_r(uid, &_pw, pwbuf, pwbuflen, &retpwptr);
 	if (err || retpwptr == NULL) {
-		if (errno == ERANGE) {
+		if (err == ERANGE) {
 			pwbuflen *= 2;
 			pwbuf = erealloc(pwbuf, pwbuflen);
 			goto try_again;