diff --git a/src/highlights-component.coffee b/src/highlights-component.coffee
index 6619eab79..383ad0154 100644
--- a/src/highlights-component.coffee
+++ b/src/highlights-component.coffee
@@ -17,7 +17,7 @@ HighlightsComponent = React.createClass
     for markerId, decorations of highlightDecorations
       if decorations?
         for decoration in decorations
-          highlightComponents.push(HighlightComponent({key: markerId + decoration.class, decoration, editor, lineHeightInPixels}))
+          highlightComponents.push(HighlightComponent({key: "#{markerId}-#{decoration.class}", decoration, editor, lineHeightInPixels}))
     highlightComponents
 
   shouldComponentUpdate: (newProps) ->