diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 73f75308..9cc2002d 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -91,4 +91,6 @@ jobs:
           path: test/test-images
 
       - name: Build docs
-        run: esy doc
+        run: |
+          opam install odoc
+          esy doc