diff --git a/extension.json b/extension.json
index d7137934..e56aafc5 100644
--- a/extension.json
+++ b/extension.json
@@ -52,6 +52,9 @@
 				"categorytree-no-pages",
 				"categorytree-error",
 				"categorytree-retry"
+			],
+			"dependencies": [
+				"mediawiki.api"
 			]
 		},
 		"ext.categoryTree.css": {