diff --git a/src/Text/Pandoc/Writers/Docx.hs b/src/Text/Pandoc/Writers/Docx.hs
index c95682331..a441aeec7 100644
--- a/src/Text/Pandoc/Writers/Docx.hs
+++ b/src/Text/Pandoc/Writers/Docx.hs
@@ -859,7 +859,7 @@ blockToOpenXML opts blk = withDirection $ blockToOpenXML' opts blk
 
 blockToOpenXML' :: (PandocMonad m) => WriterOptions -> Block -> WS m [Element]
 blockToOpenXML' _ Null = return []
-blockToOpenXML' opts (Div (ident,classes,kvs) bs) = do
+blockToOpenXML' opts (Div (ident,_classes,kvs) bs) = do
   stylemod <- case lookup dynamicStyleKey kvs of
                    Just sty -> do
                       modify $ \s ->