diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index a1a9bd9e..e6a9c27d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -27,6 +27,14 @@ jobs:
       with:
         ocaml-compiler: ${{matrix.ocaml-compiler}}
 
+    - uses: ocaml/setup-ocaml@v3
+      if: runner.os == 'Windows'
+      with:
+        ocaml-compiler: ${{matrix.ocaml-compiler}}
+        opam-repositories: |
+          opam-repository-mingw: https://github.com/ocaml-opam/opam-repository-mingw.git#sunset
+          default: https://github.com/ocaml/opam-repository.git
+
     # For caqti Postgres tests. Opam does actually install Postgres for us, however brew
     # doesn't link it by default, so we have to install and link it manually.
     - name: Prepare MacOS