diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 07c855b..bcd0de5 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -6,9 +6,15 @@ on:
       - master
   pull_request:
   workflow_dispatch:
-
-env:
-  CLEAR_LOCK_FILES: false
+    inputs:
+      clearLockFiles:
+        description: 'Clear yarn.lock files?'
+        required: true
+        default: 'no'
+        type: choice
+        options:
+          - yes
+          - no
 
 jobs:
   tests:
@@ -20,10 +26,6 @@ jobs:
       fail-fast: false
 
     steps:
-      - name: Check variables
-        if: ${{ env.CLEAR_LOCK_FILES != 'true' && env.CLEAR_LOCK_FILES != 'false' }}
-        run: echo "Variable CLEAR_LOCK_FILES is ${{ env.CLEAR_LOCK_FILES }}, but should be 'true' or 'false'" && exit 1
-
       - uses: actions/checkout@v3
       - name: Set up Node.js ${{ matrix.node-version }}
         uses: actions/setup-node@v3
@@ -47,7 +49,7 @@ jobs:
         run: npm install -g yarn
 
       - name: Clear lock files
-        if: ${{ env.CLEAR_LOCK_FILES == 'true' }}
+        if: ${{ inputs.clearLockFiles == 'yes' }}
         run: rm yarn.lock packages/*/yarn.lock
 
       - name: Install dependencies