diff --git a/lib/private/Files/Template/TemplateManager.php b/lib/private/Files/Template/TemplateManager.php
index 155be9303b1..73297869f12 100644
--- a/lib/private/Files/Template/TemplateManager.php
+++ b/lib/private/Files/Template/TemplateManager.php
@@ -213,12 +213,13 @@ class TemplateManager implements ITemplateManager {
 		foreach ($this->getRegisteredProviders() as $provider) {
 			foreach ($type->getMimetypes() as $mimetype) {
 				foreach ($provider->getCustomTemplates($mimetype) as $template) {
-					$templates[] = $template;
+					$templateId = $template->jsonSerialize()['templateId'];
+					$templates[$templateId] = $template;
 				}
 			}
 		}
 
-		return $templates;
+		return array_values($templates);
 	}
 
 	/**