diff --git a/.github/workflows/type_check.yml b/.github/workflows/type_check.yml
index e977589b5a8b5b908a7a215ed572f6deb9fb9783..4bd33ff840daacbcf5e2cb35d5b6ccd9c8bb4ccb 100644
--- a/.github/workflows/type_check.yml
+++ b/.github/workflows/type_check.yml
@@ -22,25 +22,26 @@ jobs:
     # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
     - uses: actions/checkout@v2
 
-    # Runs a single command using the runners shell
-    - name: Run a one-line script
-      run: echo Hello, world!
-
     # Runs a set of commands using the runners shell
-    - name: setup
+    - name: opam setup
       run: |
+        sudo apt install --yes emacs
         sudo wget https://github.com/ocaml/opam/releases/download/2.0.5/opam-2.0.5-x86_64-linux -O /usr/bin/opam
         sudo chmod 755 /usr/bin/opam
         opam init -a --disable-sandboxing --compiler="4.07.1"
         opam update
         opam switch "4.07.1"
-        opam $(eval env)
-        opam install alt-ergo.2.3.0
+        eval $(opam env)
+        opam install alt-ergo.2.3.0 --yes
         git clone https://github.com/Deducteam/lambdapi.git lambdapi
         (cd lambdapi || exit 1
          opam pin add -n -k path lambdapi .)
-        opam install lambdapi
-        wh3 config --full-config
-        
+        opam install --deps-only -t -d lambdapi --yes
+        (cd lambdapi || exit 1
+         make install)
+        why3 config --full-config
+
     - name: check
-      run: lambdapi check encodings/*.lp
+      run: |
+        eval $(opam env)
+        lambdapi check encodings/*.lp