diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index b783e21b..f1aa65b1 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -35,6 +35,8 @@ jobs:
           BUILD_TARGET: WebGL
           BUILDS_PATH: builds
           BUILD_METHOD: ""
+        with:
+          args: IMAGE_TARGET_ARG=a_value
 
       # Upload distributables
       - name: Upload Build
diff --git a/Dockerfile b/Dockerfile
index 94adc71b..2fa89d0d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,5 @@
 ARG IMAGE_VERSION_ARG=2019.0.00f0
-ARG IMAGE_TARGET_ARG=${IMAGE_TARGET}
+ARG IMAGE_TARGET_ARG=$1
 FROM gableroux/unity3d:${IMAGE_VERSION_ARG}-${IMAGE_TARGET_ARG}
 
 LABEL "com.github.actions.name"="Unity - Builder"