diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 9fa3e1a..4daeeaa 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -29,6 +29,7 @@ jobs:
         with:
           ocaml-compiler: ${{ matrix.ocaml-compiler }}
           dune-cache: true
+          allow-prerelease-opam: true
 
       - run: opam install -t trace trace-tef --deps-only
       - run: opam exec -- dune build '@install' -p trace,trace-tef