diff --git a/src/Carbon/AbstractTranslator.php b/src/Carbon/AbstractTranslator.php
index d56ec796..8dd47aee 100644
--- a/src/Carbon/AbstractTranslator.php
+++ b/src/Carbon/AbstractTranslator.php
@@ -157,6 +157,8 @@ public function resetMessages(?string $locale = null): bool
             return true;
         }
 
+        $this->assertValidLocale($locale);
+
         foreach ($this->getDirectories() as $directory) {
             $data = @include \sprintf('%s/%s.php', rtrim($directory, '\\/'), $locale);