diff --git a/unity/action.yaml b/unity/action.yaml
index f5fc0bb..4a1dd16 100644
--- a/unity/action.yaml
+++ b/unity/action.yaml
@@ -17,10 +17,14 @@ inputs:
   unityBuilder:
     description: "Whether or not to use the UnityBuilder instead of a Unity command."
     required: false
+  test:
+    description: "Whether or not to use the UnityBuilder instead of a Unity command."
+    required: true
+    default: unityci/base:latest
 runs:
   using: docker
   #This is a base "mock" image which is replaced by the correct image in the "unity-command" action at runtime.
-  image: docker://unityci/base:latest
+  image: docker://${{ inputs.test }}
   args:
   - ${{ inputs.serial }}
   - ${{ inputs.email }}