diff --git a/src/RegexResult.php b/src/RegexResult.php
index 62de463..f910266 100644
--- a/src/RegexResult.php
+++ b/src/RegexResult.php
@@ -6,6 +6,6 @@ abstract class RegexResult
 {
     protected static function lastPregError(): string
     {
-        return array_flip(get_defined_constants(true)['pcre'])[preg_last_error()];
+        return array_search(preg_last_error(), get_defined_constants(true)['pcre'], true);
     }
 }