3 files changed, 3 insertions, 3 deletions
diff --git a/test/Tests/Readers/Docx.hs b/test/Tests/Readers/Docx.hs
index e5bbabadf..9d0913e55 100644
--- a/test/Tests/Readers/Docx.hs
+++ b/test/Tests/Readers/Docx.hs
@@ -46,7 +46,7 @@ instance ToString NoNormPandoc where
    where s = case d of
                   NoNormPandoc (Pandoc (Meta m) _)
                     | M.null m  -> Nothing
-                    | otherwise -> Just "" -- need this to get meta output
+                    | otherwise -> Just mempty -- need this to get meta output
 
 instance ToPandoc NoNormPandoc where
   toPandoc = unNoNorm
diff --git a/test/Tests/Readers/FB2.hs b/test/Tests/Readers/FB2.hs
index e64e8a2ce..dd228aeae 100644
--- a/test/Tests/Readers/FB2.hs
+++ b/test/Tests/Readers/FB2.hs
@@ -24,7 +24,7 @@ import Data.Text.Lazy (fromStrict)
 import System.FilePath (replaceExtension)
 
 fb2ToNative :: Text -> Text
-fb2ToNative = purely (writeNative def{ writerTemplate = Just "" }) . purely (readFB2 def)
+fb2ToNative = purely (writeNative def{ writerTemplate = Just mempty }) . purely (readFB2 def)
 
 fb2Test :: TestName -> FilePath -> TestTree
 fb2Test name path = goldenVsString name native (fromTextLazy . fromStrict . fb2ToNative . toText <$> BS.readFile path)
diff --git a/test/Tests/Readers/Odt.hs b/test/Tests/Readers/Odt.hs
index d66a4e98b..9dc93c92e 100644
--- a/test/Tests/Readers/Odt.hs
+++ b/test/Tests/Readers/Odt.hs
@@ -61,7 +61,7 @@ instance ToString NoNormPandoc where
    where s = case d of
                   NoNormPandoc (Pandoc (Meta m) _)
                     | M.null m  -> Nothing
-                    | otherwise -> Just "" -- need this for Meta output
+                    | otherwise -> Just mempty -- need this for Meta output
 
 instance ToPandoc NoNormPandoc where
   toPandoc = unNoNorm