diff --git a/.github/workflows/github-actions-image.yaml b/.github/workflows/github-actions-image.yaml
new file mode 100644
index 0000000..8e4bce0
--- /dev/null
+++ b/.github/workflows/github-actions-image.yaml
@@ -0,0 +1,56 @@
+name: Github Action Docker Image
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  build-github-action-image:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          submodules: recursive
+      - name: Increase swap
+        run: |
+          free -h
+
+          sudo swapoff /mnt/swapfile
+          sudo fallocate -l 12G /mnt/swapfile
+          sudo mkswap /mnt/swapfile
+          sudo swapon /mnt/swapfile
+
+          free -h
+
+      - name: Install Nix
+        uses: cachix/install-nix-action@v12
+        with:
+          extra_nix_config: |
+            trusted-public-keys = hydra.iohk.io:f/Ea+s+dFdN+3Y/G+FDgSq+a5NEWhJGzdjvKNGv0/EQ= cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=
+            substituters = https://hydra.iohk.io https://cache.nixos.org/
+
+      - name: Login to Cachix
+        uses: cachix/cachix-action@v8
+        with:
+          name: octopod
+          signingKey: ${{ secrets.CACHIX_SIGNING_KEY }}
+
+      - name: Build Github Action Docker Image
+        run: |
+          nix-build -A compaRESTGithubAction -j auto -o image
+
+      - name: Log into Docker Hub
+        if: github.ref == 'refs/heads/master'
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKER_HUB_USERNAME }}
+          password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
+
+      - name: Upload Image to Docker Hub
+        if: github.ref == 'refs/heads/master'
+        run: |
+          docker load -i image
+          docker push typeable/comparest-github-action:latest
diff --git a/.github/workflows/haskell.yml b/.github/workflows/linux-binary.yaml
similarity index 95%
rename from .github/workflows/haskell.yml
rename to .github/workflows/linux-binary.yaml
index 0fe162f..7c7befb 100644
--- a/.github/workflows/haskell.yml
+++ b/.github/workflows/linux-binary.yaml
@@ -1,4 +1,4 @@
-name: Haskell CI
+name: Linux binary
 
 on:
   push:
@@ -27,7 +27,7 @@ jobs:
           free -h
 
           sudo swapoff /mnt/swapfile
-          sudo fallocate -l 12G /mnt/swapfile
+          sudo fallocate -l 13G /mnt/swapfile
           sudo mkswap /mnt/swapfile
           sudo swapon /mnt/swapfile
 
diff --git a/action.yaml b/action.yaml
new file mode 100644
index 0000000..b6fce0e
--- /dev/null
+++ b/action.yaml
@@ -0,0 +1,47 @@
+name: compaREST
+author: Typeable
+description: API reliability checker
+inputs:
+  GITHUB_TOKEN:
+    description: "The GitHub access token (e.g. secrets.GITHUB_TOKEN) used to create or update the comment. This defaults to {{ github.token }}."
+    default: "${{ github.token }}"
+    required: false
+  repo:
+    description: The owner of the repo in which to post the comment.
+    default: "${{ github.repository }}"
+    required: false
+  pull_request:
+    description: The pull request in which to post the comment.
+    default: "${{ github.event.pull_request.number }}"
+    required: false
+  project_name:
+    description: The name of the project to which the API pertains.
+    required: true
+  footer:
+    description: A footer that can be appended to the comment.
+    required: false
+    default: ""
+  old:
+    description: The path to old specification of the API.
+    required: true
+  new:
+    description: The path to new specification of the API.
+    required: true
+runs:
+  using: "docker"
+  image: "typeable/comparest-github-action:latest"
+  env:
+    GITHUB_TOKEN: "${{ inputs.GITHUB_TOKEN }}"
+    REPO: "${{ inputs.repo }}"
+    PR_NUMBER: "${{ inputs.pull_request }}"
+    PROJECT_NAME: "${{ inputs.project_name }}"
+    FOOTER: "${{ inputs.footer }}"
+    ROOT: "/github/workspace"
+    OLD: "${{ inputs.old }}"
+    NEW: "${{ inputs.new }}"
+  pre-entrypoint: "/bin/pre"
+  entrypoint: "/bin/run"
+
+branding:
+  icon: crosshair
+  color: gray-dark
diff --git a/app/Main.hs b/app/Main.hs
index 223fd63..76151a6 100644
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -14,6 +14,7 @@ import OpenAPI.Checker.Run
 import System.Exit
 import System.IO
 import Text.Pandoc hiding (report)
+import Text.Pandoc.Builder
 
 main :: IO ()
 main = do
@@ -47,7 +48,7 @@ main = do
           }
       (report, status) = runReport reportConfig (a, b)
   case mode opts of
-    Just _ -> either handler pure <=< runExceptT $ write report
+    Just _ -> either handler pure <=< runExceptT $ write $ doc report
     Nothing -> pure ()
   when (signalExitCode opts) $
     case status of
diff --git a/default.nix b/default.nix
index ec74316..86de6d2 100644
--- a/default.nix
+++ b/default.nix
@@ -1,33 +1,71 @@
 { sources ? import ./nix/sources.nix
 , haskellNix ? import sources.haskellNix { inherit system; }
-, pkgs ? import haskellNix.sources.nixpkgs-2105 (haskellNix.nixpkgsArgs // {inherit system;})
+, pkgs ? import haskellNix.sources.nixpkgs-2105 (haskellNix.nixpkgsArgs // { inherit system; })
 , system ? builtins.currentSystem
+, nix-filter ? import sources.nix-filter
 }:
 let
   hsPkgs = pkgs.haskell-nix.stackProject {
-    src = ./.;
+    src = nix-filter {
+      root = ./.;
+      name = "compaREST";
+      include = [
+        ./stack.yaml
+        ./stack.yaml.lock
+        ./openapi-diff.cabal
+      ];
+    };
 
     modules = [
       {
         dontStrip = false;
         dontPatchELF = false;
         enableDeadCodeElimination = true;
+        packages.openapi-diff.src = nix-filter {
+          root = ./.;
+          name = "compaREST-src";
+          include = with nix-filter; [
+            (./openapi-diff.cabal)
+            (inDirectory ./test)
+            (inDirectory ./src)
+            (inDirectory ./app)
+            (inDirectory ./github-action)
+            ./awsm-css/dist/awsm.min.css
+            ./LICENSE
+          ];
+        };
       }
     ];
   };
 
-  compaREST-static = pkgs.runCommand "compaREST-static" { } ''
-    mkdir $out
-    cp ${hsPkgs.projectCross.musl64.hsPkgs.openapi-diff.components.exes.openapi-diff + "/bin/openapi-diff"} $out/compaREST
+  staticify = name: drv: pkgs.runCommand name { } ''
+    mkdir -p $out/bin
+    cp ${drv + "/bin"}/* $out/bin
 
-    ${pkgs.nukeReferences}/bin/nuke-refs $out/compaREST
+    ${pkgs.nukeReferences}/bin/nuke-refs $out/bin/*
   '';
+
   compaREST = pkgs.dockerTools.buildImage {
     name = "compaREST";
-    contents = [compaREST-static];
+    contents = [ (staticify "compaREST-static" hsPkgs.projectCross.musl64.hsPkgs.openapi-diff.components.exes.openapi-diff) ];
     config = {
-      Entrypoint = [ "/compaREST" ];
+      Entrypoint = [ "/bin/openapi-diff" ];
     };
   };
 
-in compaREST
+  compaRESTGithubAction =
+    let
+      action = staticify "compaREST-github-action-static" hsPkgs.projectCross.musl64.hsPkgs.openapi-diff.components.exes.comparest-github-action;
+      wrapped = pkgs.runCommand "wrapped-compaREST-github-action" { buildInputs = [ pkgs.makeWrapper ]; } ''
+        makeWrapper ${action}/bin/comparest-github-action $out/bin/pre --add-flags "pre"
+        makeWrapper ${action}/bin/comparest-github-action $out/bin/run --add-flags "run"
+      '';
+    in
+    pkgs.dockerTools.buildImage {
+      name = "typeable/comparest-github-action";
+      tag = "latest";
+      contents = [ wrapped pkgs.cacert ];
+    };
+
+in
+{ inherit compaREST compaRESTGithubAction; }
diff --git a/github-action/CompaREST/GitHub/API.hs b/github-action/CompaREST/GitHub/API.hs
new file mode 100644
index 0000000..2fd526b
--- /dev/null
+++ b/github-action/CompaREST/GitHub/API.hs
@@ -0,0 +1,55 @@
+module CompaREST.GitHub.API
+  ( mapComment,
+    createOrUpdateComment,
+  )
+where
+
+import CompaREST.GitHub.Action.Config
+import Control.Monad
+import Control.Monad.Freer
+import Control.Monad.Freer.GitHub
+import Control.Monad.Freer.Reader
+import Data.Foldable
+import Data.Proxy
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified Data.Vector as V
+import GitHub
+import qualified GitHub as GH
+
+findComment :: Members '[GitHub, Reader Config] effs => Eff effs (Maybe GH.IssueComment)
+findComment = do
+  Config {..} <- ask
+  comments <- sendGitHub $ GH.commentsR repoOwner repoName issue GH.FetchAll
+  htmlComment <- getHTMLComment
+  let tryStripPrefix :: GH.IssueComment -> Maybe GH.IssueComment
+      tryStripPrefix c@GH.IssueComment {issueCommentBody = (T.stripSuffix htmlComment -> Just b)} =
+        Just $ c {GH.issueCommentBody = b}
+      tryStripPrefix _ = Nothing
+  pure . (V.!? 0) $ V.mapMaybe tryStripPrefix comments
+
+mapComment :: Members '[GitHub, Reader Config] effs => (Text -> Text) -> Eff effs ()
+mapComment f = do
+  findComment
+    >>= traverse_
+      ( \comment -> do
+          Config {..} <- ask
+          htmlComment <- getHTMLComment
+          sendGitHub $ editCommentR repoOwner repoName (GH.mkId Proxy $ GH.issueCommentId comment) ((<> htmlComment) . f $ GH.issueCommentBody comment)
+          pure ()
+      )
+
+createOrUpdateComment :: Members '[GitHub, Reader Config] effs => Text -> Eff effs ()
+createOrUpdateComment body' = do
+  Config {..} <- ask
+  htmlComment <- getHTMLComment
+  let body = body' <> htmlComment
+  void $
+    findComment >>= \case
+      Just comment -> sendGitHub $ editCommentR repoOwner repoName (GH.mkId Proxy $ GH.issueCommentId comment) body
+      Nothing -> sendGitHub $ createCommentR repoOwner repoName issue body
+
+getHTMLComment :: Member (Reader Config) effs => Eff effs Text
+getHTMLComment = do
+  name <- asks projectName
+  pure $ "\n\n<!-- compaREST comment – " <> name <> " -->"
diff --git a/github-action/CompaREST/GitHub/Action/Config.hs b/github-action/CompaREST/GitHub/Action/Config.hs
new file mode 100644
index 0000000..1761170
--- /dev/null
+++ b/github-action/CompaREST/GitHub/Action/Config.hs
@@ -0,0 +1,43 @@
+module CompaREST.GitHub.Action.Config
+  ( Config (..),
+  )
+where
+
+import Data.Proxy
+import Data.Text (Text)
+import qualified Data.Text as T
+import qualified GitHub as GH
+
+import System.Envy
+
+data Config = Config
+  { githubToken :: GH.Auth
+  , repoOwner :: GH.Name GH.Owner
+  , repoName :: GH.Name GH.Repo
+  , issue :: GH.IssueNumber
+  , projectName :: Text
+  , footerText :: Text
+  , root :: FilePath
+  }
+
+instance FromEnv Config where
+  fromEnv _ = do
+    token <- GH.OAuth <$> env "GITHUB_TOKEN"
+    (owner, repo) <-
+      T.split (== '/') <$> env "REPO" >>= \case
+        [owner, name] -> pure (owner, name)
+        _ -> fail "malformed repo"
+    issue <- GH.IssueNumber <$> env "PR_NUMBER"
+    projectName <- env "PROJECT_NAME"
+    footerText <- env "FOOTER"
+    root <- envMaybe "ROOT" .!= "."
+    pure $
+      Config
+        { githubToken = token
+        , repoOwner = GH.mkName Proxy owner
+        , repoName = GH.mkName Proxy repo
+        , issue = issue
+        , projectName = projectName
+        , footerText = footerText
+        , root = root
+        }
diff --git a/github-action/Control/Monad/Freer/GitHub.hs b/github-action/Control/Monad/Freer/GitHub.hs
new file mode 100644
index 0000000..6579746
--- /dev/null
+++ b/github-action/Control/Monad/Freer/GitHub.hs
@@ -0,0 +1,27 @@
+module Control.Monad.Freer.GitHub
+  ( GitHub (..),
+    runGitHub,
+    sendGitHub,
+  )
+where
+
+import Control.Monad.Freer
+import Control.Monad.Freer.Error
+import Control.Monad.IO.Class
+import Data.Aeson
+import GitHub hiding (Error)
+import qualified GitHub as GH
+
+data GitHub r where
+  SendGHRequest :: FromJSON x => Request 'RW x -> GitHub x
+
+runGitHub :: (Member (Error GH.Error) effs, MonadIO (Eff effs)) => Auth -> Eff (GitHub ': effs) ~> Eff effs
+runGitHub auth =
+  interpret
+    ( \(SendGHRequest req) ->
+        liftIO (executeRequest auth req)
+          >>= either throwError pure
+    )
+
+sendGitHub :: (FromJSON x, Member GitHub effs) => Request 'RW x -> Eff effs x
+sendGitHub req = send $ SendGHRequest req
diff --git a/github-action/Main.hs b/github-action/Main.hs
new file mode 100644
index 0000000..5ba7b6c
--- /dev/null
+++ b/github-action/Main.hs
@@ -0,0 +1,87 @@
+module Main (main) where
+
+import CompaREST.GitHub.API
+import CompaREST.GitHub.Action.Config
+import Control.Exception
+import Control.Monad.Freer
+import Control.Monad.Freer.Error
+import Control.Monad.Freer.GitHub
+import Control.Monad.Freer.Reader
+import Data.Text (Text)
+import qualified Data.Yaml.Aeson as Yaml
+import qualified GitHub as GH
+import OpenAPI.Checker.Run
+import System.Environment
+import System.Envy (decodeEnv)
+import System.FilePath ((</>))
+import Text.Pandoc (runPure)
+import Text.Pandoc.Builder
+import Text.Pandoc.Options
+import Text.Pandoc.Writers
+
+main :: IO ()
+main = do
+  cfg <- decodeEnv >>= either error pure
+  getArgs >>= \case
+    ["pre"] -> runPre cfg
+    ["run"] -> do
+      oldFile <- getEnv "OLD"
+      newFile <- getEnv "NEW"
+      runRun cfg (root cfg </> oldFile) (root cfg </> newFile)
+    _ -> error "Invalid arguments."
+
+runner :: Config -> Eff '[GitHub, Error GH.Error, Reader Config, IO] a -> IO a
+runner cfg =
+  runM @IO . runReader cfg
+    . flip (handleError @GH.Error) (error . displayException)
+    . runGitHub (githubToken cfg)
+
+runPre :: Config -> IO ()
+runPre cfg =
+  runner cfg $
+    mapComment
+      (markdown (header 4 "⏳ Report might not be accurate. Attempting to update." <> horizontalRule) <>)
+
+runRun :: Config -> FilePath -> FilePath -> IO ()
+runRun cfg old' new' = runner cfg $ do
+  old <- Yaml.decodeFileThrow old'
+  new <- Yaml.decodeFileThrow new'
+  let reportConfig =
+        ReportConfig
+          { treeStyle = FoldingBlockquotesTreeStyle
+          , reportMode = All
+          }
+      (report, status) = runReport reportConfig (old, new)
+
+      summaryDetail s d =
+        rawHtml "<details>"
+          <> rawHtml "<summary>"
+          <> s
+          <> rawHtml "</summary>"
+          <> d
+          <> rawHtml "</details>"
+        where
+          rawHtml = rawBlock "html"
+
+      message =
+        header 3 (text $ "⛄ compaREST – " <> projectName cfg)
+          <> if old == new
+            then header 1 "✅ The API did not change"
+            else
+              header
+                1
+                ( case status of
+                    BreakingChanges -> "⚠️ Breaking changes found!"
+                    NoBreakingChanges -> "No breaking changes found ✨"
+                    OnlyUnsupportedChanges -> "🤷 Couldn't determine compatibility"
+                )
+                <> summaryDetail (plain "ℹ️ Details") report
+      messageBody = markdown message <> "\n\n" <> footerText cfg
+  createOrUpdateComment messageBody
+
+markdown :: Blocks -> Text
+markdown =
+  either (error . displayException) id
+    . runPure
+    . writeHtml5String def
+    . doc
diff --git a/nix/sources.json b/nix/sources.json
index a17dbc5..4275e52 100644
--- a/nix/sources.json
+++ b/nix/sources.json
@@ -5,10 +5,10 @@
         "homepage": "https://input-output-hk.github.io/haskell.nix",
         "owner": "input-output-hk",
         "repo": "haskell.nix",
-        "rev": "8c587f90d2986f87a8212c3469521db512bc7ed9",
-        "sha256": "0a4mz47ccvl1nl2p08zbn33i1vmak4bjr4z6wqzzflnq90hg5a0s",
+        "rev": "1992b910e9b4d880e1f4639f4fe7266bceb9a5ad",
+        "sha256": "15w3wixjnb52f7cj3s94fy0zc0l1gc94p3n2wyq3qqxj10hvirfw",
         "type": "tarball",
-        "url": "https://github.com/input-output-hk/haskell.nix/archive/8c587f90d2986f87a8212c3469521db512bc7ed9.tar.gz",
+        "url": "https://github.com/input-output-hk/haskell.nix/archive/1992b910e9b4d880e1f4639f4fe7266bceb9a5ad.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "niv": {
@@ -22,5 +22,17 @@
         "type": "tarball",
         "url": "https://github.com/nmattia/niv/archive/e0ca65c81a2d7a4d82a189f1e23a48d59ad42070.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
+    },
+    "nix-filter": {
+        "branch": "master",
+        "description": "a small self-container source filtering lib",
+        "homepage": "",
+        "owner": "numtide",
+        "repo": "nix-filter",
+        "rev": "3c9e33ed627e009428197b07216613206f06ed80",
+        "sha256": "19w142crrkywxynmyw4rhz4nglrg64yjawfkw3j91qwkwbfjds84",
+        "type": "tarball",
+        "url": "https://github.com/numtide/nix-filter/archive/3c9e33ed627e009428197b07216613206f06ed80.tar.gz",
+        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     }
 }
diff --git a/openapi-diff.cabal b/openapi-diff.cabal
index 3018741..cbbf8e9 100644
--- a/openapi-diff.cabal
+++ b/openapi-diff.cabal
@@ -38,7 +38,6 @@ common common-options
     -fconstraint-solver-iterations=0
   default-language:    Haskell2010
   build-depends:       base >= 4.12.0.0 && < 4.16
-                     , bytestring
                      , text
 
   default-extensions: ApplicativeDo
@@ -111,6 +110,7 @@ library
                      , file-embed
                      , data-default
                      , ordered-containers
+                     , bytestring
   hs-source-dirs:      src
   exposed-modules:  Data.HList
                   , OpenAPI.Checker.Behavior
@@ -167,6 +167,7 @@ executable openapi-diff
     , aeson
     , containers
     , doctemplates
+    , pandoc-types
   ghc-options:         -threaded
                        -rtsopts
                        -with-rtsopts=-N
@@ -174,6 +175,29 @@ executable openapi-diff
     FormatHeuristic
     OpenAPI.Checker.Options
 
+executable comparest-github-action
+  import:              common-options
+  hs-source-dirs:      github-action
+  main-is:             Main.hs
+  build-depends:
+      openapi-diff
+    , pandoc
+    , yaml
+    , aeson
+    , github
+    , freer-simple
+    , vector
+    , pandoc-types
+    , envy
+    , filepath
+  ghc-options:         -threaded
+                       -rtsopts
+                       -with-rtsopts=-N
+  other-modules:
+    Control.Monad.Freer.GitHub
+    CompaREST.GitHub.API
+    CompaREST.GitHub.Action.Config
+
 test-suite openapi-diff-test
   import:              common-options
   type:                exitcode-stdio-1.0
@@ -193,6 +217,7 @@ test-suite openapi-diff-test
     , pandoc
     , data-default
     , lens
+    , pandoc-types
   ghc-options:         -threaded
                        -rtsopts
                        -with-rtsopts=-N
diff --git a/src/OpenAPI/Checker/Report.hs b/src/OpenAPI/Checker/Report.hs
index 22ffcfd..73a7503 100644
--- a/src/OpenAPI/Checker/Report.hs
+++ b/src/OpenAPI/Checker/Report.hs
@@ -104,7 +104,7 @@ data ReportTreeStyle = HeadersTreeStyle | FoldingBlockquotesTreeStyle
 twoRowTable :: [(Inlines, Inlines)] -> Blocks
 twoRowTable x = simpleTable (para . fst <$> x) [para . snd <$> x]
 
-generateReport :: ReportConfig -> ReportInput -> (Pandoc, ReportStatus)
+generateReport :: ReportConfig -> ReportInput -> (Blocks, ReportStatus)
 generateReport cfg inp =
   let
       schemaIssuesPresent = not $ P.null $ schemaIssues inp
@@ -116,7 +116,6 @@ generateReport cfg inp =
         OnlyErrors -> False
       builder = buildReport cfg
       report =
-        doc $
           header 1 "Summary"
             <> twoRowTable
               (when'
diff --git a/src/OpenAPI/Checker/Run.hs b/src/OpenAPI/Checker/Run.hs
index ac32e64..3fb4db0 100644
--- a/src/OpenAPI/Checker/Run.hs
+++ b/src/OpenAPI/Checker/Run.hs
@@ -11,6 +11,7 @@ import OpenAPI.Checker.Paths
 import OpenAPI.Checker.Report
 import OpenAPI.Checker.Subtree
 import OpenAPI.Checker.Validate.OpenApi ()
+import Text.Pandoc.Builder
 
 runChecker :: (OpenApi, OpenApi) -> CheckerOutput
 runChecker (client, server) =
@@ -26,5 +27,5 @@ runChecker (client, server) =
         }
     run p c = either id mempty . runCompatFormula . checkCompatibility Root HNil $ toPC p c
 
-runReport :: ReportConfig -> (OpenApi, OpenApi) -> (Pandoc, ReportStatus)
+runReport :: ReportConfig -> (OpenApi, OpenApi) -> (Blocks, ReportStatus)
 runReport cfg = generateReport cfg . segregateIssues . runChecker
diff --git a/stack.yaml b/stack.yaml
index 5d01ff5..84830be 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,8 +1,11 @@
-resolver: lts-18.2
+resolver: lts-18.4
 
 extra-deps:
   - open-union-0.4.0.0
   - type-fun-0.1.3
+  - github-0.26
+  - base16-bytestring-0.1.1.7
+  - http-link-header-1.0.3.1
 
 apply-ghc-options: everything
 rebuild-ghc-options: true
diff --git a/stack.yaml.lock b/stack.yaml.lock
index c0bbcb3..daa599e 100644
--- a/stack.yaml.lock
+++ b/stack.yaml.lock
@@ -18,9 +18,30 @@ packages:
       sha256: b977d42525f0b4223959918d18e7905085283e937493c395077b608cd19b42c1
   original:
     hackage: type-fun-0.1.3
+- completed:
+    hackage: github-0.26@sha256:a9d4046325c3eb28cdc7bef2c3f5bb213328caeae0b7dce6f51de655f0bffaa1,7162
+    pantry-tree:
+      size: 7511
+      sha256: b71aab2984b268030c9e2617043575681134c1fe60dffbd5596e659c0a3e9aec
+  original:
+    hackage: github-0.26
+- completed:
+    hackage: base16-bytestring-0.1.1.7@sha256:0021256a9628971c08da95cb8f4d0d72192f3bb8a7b30b55c080562d17c43dd3,2231
+    pantry-tree:
+      size: 454
+      sha256: 2dc99cd67293b09204098202d0bdcdcf89d2b8c69ce6c8f4e31deadbdab2a7f9
+  original:
+    hackage: base16-bytestring-0.1.1.7
+- completed:
+    hackage: http-link-header-1.0.3.1@sha256:9917c26635a46eff5d36c5344a4ae42fad2b5de79c0e300363bddd5eec66facd,1937
+    pantry-tree:
+      size: 990
+      sha256: 155feaf856daf5b55491048c8c4726ba765a8fe79263ebdbfc82f6c385a15715
+  original:
+    hackage: http-link-header-1.0.3.1
 snapshots:
 - completed:
-    size: 585392
-    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/18/2.yaml
-    sha256: 7abb45c0cc5eb349448b66d8753655542d45d387ad26970419282eab3d860724
-  original: lts-18.2
+    size: 585817
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/18/4.yaml
+    sha256: ea3a318eafa9e9cc56bfbe46099fd0d54d32641ab7bbe1d182ed8f5de39f804c
+  original: lts-18.4
diff --git a/test/Spec/Golden/TraceTree.hs b/test/Spec/Golden/TraceTree.hs
index 927d951..7ce1cc8 100644
--- a/test/Spec/Golden/TraceTree.hs
+++ b/test/Spec/Golden/TraceTree.hs
@@ -1,5 +1,5 @@
 module Spec.Golden.TraceTree
-  ( tests
+  ( tests,
   )
 where
 
@@ -14,6 +14,7 @@ import OpenAPI.Checker.Run
 import OpenAPI.Checker.Validate.OpenApi ()
 import Spec.Golden.Extra
 import Test.Tasty (TestTree, testGroup)
+import Text.Pandoc.Builder
 import Text.Pandoc.Class
 import Text.Pandoc.Options
 import Text.Pandoc.Writers
@@ -37,7 +38,7 @@ tests = do
       "report.md"
       ("a.yaml", "b.yaml")
       Yaml.decodeFileThrow
-      (runPandoc . writeMarkdown def {writerExtensions = githubMarkdownExtensions} . fst . runReport def)
+      (runPandoc . writeMarkdown def {writerExtensions = githubMarkdownExtensions} . doc . fst . runReport def)
 
   return $ testGroup "Golden tests" [traceTreeTests, reportTests]