diff --git a/.github/workflows/docker-action.yml b/.github/workflows/docker-action.yml
index 0216ceb..dc43cf0 100644
--- a/.github/workflows/docker-action.yml
+++ b/.github/workflows/docker-action.yml
@@ -1,3 +1,5 @@
+# Beware not to destroy this file when regenerating it from meta.yml
+
 name: Docker CI
 
 on:
@@ -25,6 +27,14 @@ jobs:
         with:
           opam_file: 'coq-bignums.opam'
           custom_image: ${{ matrix.image }}
+          install: |
+            startGroup "Install dependencies"
+              # sudo apt-get update -y -q
+              opam remove -y coq-bignums # remove coq-bignums already in image
+              opam pin add -n -y -k path $PACKAGE $WORKDIR
+              opam update -y
+              opam install --confirm-level=unsafe-yes -j 2 $PACKAGE --deps-only
+            endGroup
           export: 'OPAMWITHTEST'
         env:
           OPAMWITHTEST: 'true'
diff --git a/coq-bignums.opam b/coq-bignums.opam
index 0ac2f8d..16e28ce 100644
--- a/coq-bignums.opam
+++ b/coq-bignums.opam
@@ -13,10 +13,12 @@ This Coq library provides BigN, BigZ, and BigQ that used to
 be part of the standard library."""
 
 build: [make "-j%{jobs}%"]
-run-test: [make "-C" "tests" "-j%{jobs}%"]
-install: [make "install"]
+install: [
+  [make "install"]
+  [make "-C" "tests" "-j%{jobs}%"] {with-test}
+]
 depends: [
-  "ocaml" 
+  "ocaml"
   "coq" {= "dev"}
 ]