diff --git a/packages/core/src/ExtensionManager.ts b/packages/core/src/ExtensionManager.ts
index a81ffb6f..cf6d15b2 100644
--- a/packages/core/src/ExtensionManager.ts
+++ b/packages/core/src/ExtensionManager.ts
@@ -1,4 +1,3 @@
-import deepmerge from 'deepmerge'
 import collect from 'collect.js'
 import { Plugin } from 'prosemirror-state'
 import { keymap } from 'prosemirror-keymap'