diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 1550cff..2ee6fa0 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -15,7 +15,10 @@ jobs:
       - run: opam install . --deps-only --with-test
       - run: opam exec -- dune build
       - run: opam exec -- dune runtest
-      - run: opam exec -- dune build @doc
+      - name: Build doc
+        run: |
+          opam install odoc
+          opam exec -- dune build @doc
       - name: Upload website artifact
         uses: actions/upload-pages-artifact@v2
         with: