diff --git a/Input/StringInput.php b/Input/StringInput.php
index 76f1d5030..56bb66cbf 100644
--- a/Input/StringInput.php
+++ b/Input/StringInput.php
@@ -24,7 +24,8 @@
  */
 class StringInput extends ArgvInput
 {
-    public const REGEX_STRING = '([^\s\\\\]+?)';
+    public const REGEX_STRING = '([^\s]+?)(?:\s|(?<!\\\\)"|(?<!\\\\)\'|$)';
+    public const REGEX_UNQUOTED_STRING = '([^\s\\\\]+?)';
     public const REGEX_QUOTED_STRING = '(?:"([^"\\\\]*(?:\\\\.[^"\\\\]*)*)"|\'([^\'\\\\]*(?:\\\\.[^\'\\\\]*)*)\')';
 
     /**
@@ -64,7 +65,7 @@ private function tokenize(string $input): array
                 $token .= $match[1].$match[2].stripcslashes(str_replace(['"\'', '\'"', '\'\'', '""'], '', substr($match[3], 1, -1)));
             } elseif (preg_match('/'.self::REGEX_QUOTED_STRING.'/A', $input, $match, 0, $cursor)) {
                 $token .= stripcslashes(substr($match[0], 1, -1));
-            } elseif (preg_match('/'.self::REGEX_STRING.'/A', $input, $match, 0, $cursor)) {
+            } elseif (preg_match('/'.self::REGEX_UNQUOTED_STRING.'/A', $input, $match, 0, $cursor)) {
                 $token .= $match[1];
             } else {
                 // should never happen