diff --git a/.github/workflows/elixir.yml b/.github/workflows/elixir.yml
index 95ca8314..ae1c23cc 100644
--- a/.github/workflows/elixir.yml
+++ b/.github/workflows/elixir.yml
@@ -36,7 +36,7 @@ jobs:
           restore-keys: |
             ${{ runner.os }}-mix-
       - name: Install dependencies
-        run: mix deps.get
+        run: mix deps.get --check-locked
 
   format:
     name: Formatting checks