diff --git a/.github/workflows/esperanto.yml b/.github/workflows/esperanto.yml
index 3a4d131..889eac1 100644
--- a/.github/workflows/esperanto.yml
+++ b/.github/workflows/esperanto.yml
@@ -12,6 +12,7 @@ jobs:
     - uses: ocaml/setup-ocaml@v2
       with:
         ocaml-compiler: ${{ matrix.ocaml-version }}
+        opam-disable-sandboxing: true
 # See jart/cosmopolitan#3
     - name: Fix binfmt and Cosmopolitan
       run: sudo sh -c "echo ':APE:M::MZqFpD::/bin/sh:' >/proc/sys/fs/binfmt_misc/register"