diff --git a/action.yml b/action.yml
index 68e85d8..24da43a 100644
--- a/action.yml
+++ b/action.yml
@@ -1,6 +1,11 @@
 name: Setup composer
 description: Install and cache composer dependencies
 author: Jamie Schouten
+inputs:
+  file:
+    description: 'file to hash for cache key'
+    required: false
+    default: '**/composer.lock'
 
 runs:
   using: "composite"
@@ -19,7 +24,7 @@ runs:
     - uses: actions/cache@v4
       with:
         path: ${{ steps.composer-cache.outputs.dir }}
-        key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+        key: ${{ runner.os }}-composer-${{ hashFiles(inputs.file) }}
         restore-keys: |
           ${{ runner.os }}-composer-