diff --git a/packages/slate-react/src/components/leaf.js b/packages/slate-react/src/components/leaf.js
index d69da00a4..d25c647e6 100644
--- a/packages/slate-react/src/components/leaf.js
+++ b/packages/slate-react/src/components/leaf.js
@@ -5,7 +5,6 @@ import Types from 'prop-types'
 import SlateTypes from 'slate-prop-types'
 
 import OffsetKey from '../utils/offset-key'
-import { IS_FIREFOX } from '../constants/environment'
 
 /**
  * Debugger.