diff --git a/benchmarks/aeson-benchmarks.cabal b/benchmarks/aeson-benchmarks.cabal
index a841a7884..ff8275628 100644
--- a/benchmarks/aeson-benchmarks.cabal
+++ b/benchmarks/aeson-benchmarks.cabal
@@ -104,6 +104,12 @@ executable aeson-benchmark-suite
     other-modules: Compare.JsonBuilder
     build-depends: json-builder
 
+  if impl(ghc >=8.10)
+    build-depends: hermes-json >=0.2.0.1
+    other-modules:
+      CompareWithHermes
+      Twitter.Hermes
+
   if !flag(text2)
     -- buffer-builder might work with text-2 sometime
     build-depends: buffer-builder
diff --git a/benchmarks/bench/CompareWithHermes.hs b/benchmarks/bench/CompareWithHermes.hs
new file mode 100644
index 000000000..3f7c094be
--- /dev/null
+++ b/benchmarks/bench/CompareWithHermes.hs
@@ -0,0 +1,69 @@
+{-# LANGUAGE NoImplicitPrelude #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+module CompareWithHermes (benchmark) where
+
+import Prelude.Compat
+import Bench
+
+import Data.Maybe (fromMaybe)
+import qualified Data.Aeson as A
+import qualified Data.Aeson.Decoding as A.D
+import qualified Data.Aeson.Parser.Internal as I
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as BL
+import qualified Data.Hermes as H
+import qualified Twitter as T
+import Twitter.Manual () -- fair comparison with manual Hermes decoders
+import Twitter.Hermes
+
+import Utils
+
+decode :: BL.ByteString -> T.Result
+decode s = fromMaybe (error "fail to parse via Aeson") $ A.decode s
+
+decode' :: BL.ByteString -> T.Result
+decode' s = fromMaybe (error "fail to parse via Aeson") $ A.decode' s
+
+decodeS :: BS.ByteString -> T.Result
+decodeS s = fromMaybe (error "fail to parse via Aeson") $ A.decodeStrict' s
+
+decodeTS :: BS.ByteString -> T.Result
+decodeTS s = fromMaybe (error "fail to parse via Aeson") $ A.D.decodeStrict s
+
+decodeIP :: BL.ByteString -> T.Result
+decodeIP s = fromMaybe (error "fail to parse via Parser.decodeWith") $
+    I.decodeWith I.jsonEOF A.fromJSON s
+
+decodeH :: BS.ByteString -> T.Result
+decodeH s = case H.decodeEither twitterResultDecoder s of
+  Right result -> result
+  Left err -> error (show err)
+
+benchmark :: Benchmark
+benchmark =
+  env (readL enFile) $ \enA ->
+  env (readS enFile) $ \enS ->
+  env (readL jpFile) $ \jpA ->
+  env (readS jpFile) $ \jpS ->
+  bgroup "compare-hermes" [
+      bgroup "decode" [
+        bgroup "en" [
+          bench "aeson/lazy"     $ nf decode enA
+        , bench "aeson/strict"   $ nf decode' enA
+        , bench "aeson/stricter" $ nf decodeS enS
+        , bench "aeson/parser"   $ nf decodeIP enA
+        , bench "aeson/tokens/strict" $ nf decodeTS enS
+        , bench "hermes"         $ nf decodeH enS
+        ]
+      , bgroup "jp" [
+          bench "aeson"          $ nf decode jpA
+        , bench "aeson/stricter" $ nf decodeS jpS
+        , bench "aeson/tokens/strict" $ nf decodeTS jpS
+        , bench "hermes"         $ nf decodeH jpS
+        ]
+      ]
+    ]
+  where
+    enFile = "twitter100.json"
+    jpFile = "jp100.json"
diff --git a/benchmarks/bench/Twitter/Hermes.hs b/benchmarks/bench/Twitter/Hermes.hs
new file mode 100644
index 000000000..290079a83
--- /dev/null
+++ b/benchmarks/bench/Twitter/Hermes.hs
@@ -0,0 +1,50 @@
+{-# LANGUAGE NoImplicitPrelude #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Twitter.Hermes where
+
+import Prelude.Compat
+
+import Data.Int (Int64)
+
+import qualified Data.Hermes as H
+import qualified Twitter as T
+
+twitterResultDecoder :: H.Value -> H.Decoder T.Result
+twitterResultDecoder = H.withObject $ \obj ->
+  T.Result
+    <$> H.atKey "results" (H.list storyDecoder) obj
+    <*> H.atKey "max_id" int64 obj
+    <*> H.atKey "since_id" int64 obj
+    <*> H.atKey "refresh_url" H.text obj
+    <*> H.atKey "next_page" H.text obj
+    <*> H.atKey "results_per_page" H.int obj
+    <*> H.atKey "page" H.int obj
+    <*> H.atKey "completed_in" H.double obj
+    <*> H.atKey "since_id_str" H.text obj
+    <*> H.atKey "max_id_str" H.text obj
+    <*> H.atKey "query" H.text obj
+
+storyDecoder :: H.Value -> H.Decoder T.Story
+storyDecoder = H.withObject $ \obj ->
+  T.Story
+    <$> H.atKey "from_user_id_str" H.text obj
+    <*> H.atKey "profile_image_url" H.text obj
+    <*> H.atKey "created_at" H.text obj
+    <*> H.atKey "from_user" H.text obj
+    <*> H.atKey "id_str" H.text obj
+    <*> H.atKey "metadata" metadataDecoder obj
+    <*> H.atKey "to_user_id" (H.nullable int64) obj
+    <*> H.atKey "text" H.text obj
+    <*> H.atKey "id" int64 obj
+    <*> H.atKey "from_user_id" int64 obj 
+    <*> pure Nothing -- our bench corpus doesn't have any geolocated tweets
+    <*> H.atKey "iso_language_code" H.text obj
+    <*> H.atKey "to_user_id_str" (H.nullable H.text) obj
+    <*> H.atKey "source" H.text obj
+
+int64 :: H.Value -> H.Decoder Int64
+int64 = fmap fromIntegral <$> H.int
+
+metadataDecoder :: H.Value -> H.Decoder T.Metadata
+metadataDecoder = H.withObject $ \obj ->
+  T.Metadata <$> H.atKey "result_type" H.text obj
diff --git a/benchmarks/bench/aeson-benchmark-suite.hs b/benchmarks/bench/aeson-benchmark-suite.hs
index 729a529f3..7d5ff9615 100644
--- a/benchmarks/bench/aeson-benchmark-suite.hs
+++ b/benchmarks/bench/aeson-benchmark-suite.hs
@@ -29,6 +29,12 @@ import qualified AesonMap
 import qualified AutoCompare
 import qualified Compare
 import qualified CompareWithJSON
+<<<<<<< HEAD:benchmarks/bench/aeson-benchmark-suite.hs
+=======
+#ifdef MIN_VERSION_hermes_json
+import qualified CompareWithHermes
+#endif
+>>>>>>> Use hermes only with GHC > 8.8:benchmarks/bench/Suite.hs
 import qualified Dates
 import qualified GitHub
 import qualified Issue673
@@ -42,6 +48,10 @@ import           Utils
 import qualified UnescapePureText1          as Text1
 #endif
 
+#if __GLASGOW_HASKELL__ >=810
+import qualified CompareWithHermes
+#endif
+
 -------------------------------------------------------------------------------
 -- Decode bench
 -------------------------------------------------------------------------------
@@ -136,3 +146,6 @@ main = do
     ]
     ++ Compare.benchmarks -- compares to different libs (encoding)
     ++ [ CompareWithJSON.benchmark ]
+#if __GLASGOW_HASKELL__ >=810
+    ++ [ CompareWithHermes.benchmark ]
+#endif
diff --git a/cabal.project b/cabal.project
index 0fad60de7..ca7375fcb 100644
--- a/cabal.project
+++ b/cabal.project
@@ -6,5 +6,7 @@ packages: benchmarks
 tests: true
 benchmarks: true
 
+allow-newer: hermes-json:attoparsec-iso8601
+
 -- packages: https://hackage.haskell.org/package/libperf-0.1/candidate/libperf-0.1.tar.gz
 -- packages: https://hackage.haskell.org/package/tasty-perfbench-0.1/candidate/tasty-perfbench-0.1.tar.gz