diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-Esqueleto [![TravisCI](https://travis-ci.org/bitemyapp/esqueleto.svg)](https://travis-ci.org/bitemyapp/esqueleto)
+Esqueleto [![CI](https://github.com/bitemyapp/esqueleto/actions/workflows/haskell.yml/badge.svg?branch=master)](https://github.com/bitemyapp/esqueleto/actions/workflows/haskell.yml)
 ==========
 
 ![Skeleton](./esqueleto.png)
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,9 @@
+3.4.2.2
+=======
+- @parsonsmatt
+  - [#255](https://github.com/bitemyapp/esqueleto/pull/255)
+    - Fix a bug where a composite primary key in a `groupBy` clause would break.
+
 3.4.2.1
 =======
 - @parsonsmatt
diff --git a/esqueleto.cabal b/esqueleto.cabal
--- a/esqueleto.cabal
+++ b/esqueleto.cabal
@@ -1,7 +1,7 @@
 cabal-version: 1.12
 
 name:           esqueleto
-version:        3.4.2.1
+version:        3.4.2.2
 synopsis:       Type-safe EDSL for SQL queries on persistent backends.
 description:    @esqueleto@ is a bare bones, type-safe EDSL for SQL queries that works with unmodified @persistent@ SQL backends.  Its language closely resembles SQL, so you don't have to learn new concepts, just new syntax, and it's fairly easy to predict the generated SQL and optimize it for your backend. Most kinds of errors committed when writing SQL are caught as compile-time errors---although it is possible to write type-checked @esqueleto@ queries that fail at runtime.
                 .
@@ -47,7 +47,7 @@
     build-depends:
         base >=4.8 && <5.0
       , aeson >=1.0
-      , attoparsec >= 0.13 && < 0.14
+      , attoparsec >= 0.13 && < 0.15
       , blaze-html
       , bytestring
       , conduit >=1.3
diff --git a/src/Database/Esqueleto/Internal/Internal.hs b/src/Database/Esqueleto/Internal/Internal.hs
--- a/src/Database/Esqueleto/Internal/Internal.hs
+++ b/src/Database/Esqueleto/Internal/Internal.hs
@@ -3003,7 +3003,7 @@
 
     match :: SomeValue -> (TLB.Builder, [PersistValue])
     match (SomeValue (ERaw _ f)) = f info
-    match (SomeValue (ECompositeKey f)) = (mconcat $ f info, mempty)
+    match (SomeValue (ECompositeKey f)) = (uncommas $ f info, mempty)
     match (SomeValue (EAliasedValue i _)) = aliasedValueIdentToRawSql i info
     match (SomeValue (EValueReference i i')) = valueReferenceToRawSql i i' info
 
diff --git a/test/Common/Test.hs b/test/Common/Test.hs
--- a/test/Common/Test.hs
+++ b/test/Common/Test.hs
@@ -34,6 +34,8 @@
     , cleanUniques
     , RunDbMonad
     , Run
+    , updateRethrowingQuery
+    , selectRethrowingQuery
     , p1, p2, p3, p4, p5
     , l1, l2, l3
     , u1, u2, u3, u4
@@ -1464,6 +1466,21 @@
                                 , (Entity p1k p1, Value 3)
                                 , (Entity p3k p3, Value 7) ]
 
+    it "GROUP BY works with composite primary key" $ run $ do
+        p1k <- insert $ Point 1 2 "asdf"
+        p2k <- insert $ Point 2 3 "asdf"
+        ret <-
+            selectRethrowingQuery $
+            from $ \point -> do
+            where_ $ point ^. PointName ==. val "asdf"
+            groupBy (point ^. PointId)
+            pure (point ^. PointId)
+        liftIO $ do
+            ret `shouldMatchList`
+                map Value [p1k, p2k]
+
+
+
     it "GROUP BY works with COUNT and InnerJoin" $ run $ do
         l1k <- insert l1
         l3k <- insert l3
@@ -2578,3 +2595,17 @@
     `catch` \(SomeException e) -> do
       (text, _) <- renderQuerySelect query
       liftIO . throwIO . userError $ Text.unpack text <> "\n\n" <> show e
+
+updateRethrowingQuery
+    ::
+    ( MonadUnliftIO  m
+    , PersistEntity val
+    , BackendCompatible SqlBackend (PersistEntityBackend val)
+    )
+    => (SqlExpr (Entity val) -> SqlQuery ())
+    -> SqlWriteT m ()
+updateRethrowingQuery k =
+    update k
+        `catch` \(SomeException e) -> do
+            (text, _) <- renderQueryUpdate (from k)
+            liftIO . throwIO . userError $ Text.unpack text <> "\n\n" <> show e