diff --git a/src/Symfony/Component/Console/Helper/QuestionHelper.php b/src/Symfony/Component/Console/Helper/QuestionHelper.php
index 593b01b39da85..dd0e67d89910c 100644
--- a/src/Symfony/Component/Console/Helper/QuestionHelper.php
+++ b/src/Symfony/Component/Console/Helper/QuestionHelper.php
@@ -317,7 +317,7 @@ private function autocomplete(OutputInterface $output, Question $question, $inpu
                     $ofs += ('A' === $c[2]) ? -1 : 1;
                     $ofs = ($numMatches + $ofs) % $numMatches;
                 }
-            } elseif (\ord($c) < 32) {
+            } elseif ('' === $c || \ord($c) < 32) {
                 if ("\t" === $c || "\n" === $c) {
                     if ($numMatches > 0 && -1 !== $ofs) {
                         $ret = (string) $matches[$ofs];