diff --git a/Classes/Service/MailTemplateService.php b/Classes/Service/MailTemplateService.php
index 4bd6084e40378de062e5617babc19d44bd2e9f60..6b3721be1163eb0b1d02243f8c13768dbbc08492 100644
--- a/Classes/Service/MailTemplateService.php
+++ b/Classes/Service/MailTemplateService.php
@@ -827,7 +827,7 @@ class MailTemplateService {
 			$extensionConfigDirectory = ExtensionManagementUtility::extPath($extension);
 			$extensionConfigDirectory .= self::CONFIG_PATH;
 
-			if (!\is_dir($extensionConfigDirectory)) {
+			if (!\is_file($extensionConfigDirectory . '/' . self::REGISTER_FILE)) {
 				continue;
 			}