diff --git a/unity-command/action.yaml b/unity-command/action.yaml
index b292b9b..357df61 100644
--- a/unity-command/action.yaml
+++ b/unity-command/action.yaml
@@ -42,13 +42,18 @@ runs:
       platform: ${{ inputs.platform }}
   - name: "Pull Unity container."
     run: |
-      CONTAINER=${{ steps.getContainer.outputs.container }}
+      CONTAINER="${{ steps.getContainer.outputs.container }}"
 
-      # Activate the license on build.
-      DOCKER_BUILDKIT=1 \
-      SERIAL="${{ inputs.serial }}" USERNAME="${{ inputs.email }}" PASSWORD="${{ inputs.password }}" \
-      docker build --secret id=SERIAL,env=SERIAL --secret id=USERNAME,env=USERNAME --secret id=PASSWORD,env=PASSWORD \
-      -t ${{ inputs.imageTag }} --build-arg IMAGE=$CONTAINER ${{ github.action_path }}
+      CACHED_CONTAINER="$CONTAINER-activated"
+      if [[ -z "$(docker image ls | grep $CACHED_CONTAINER)" ]]; then
+        # Activate the license on build.
+        DOCKER_BUILDKIT=1 \
+        SERIAL="${{ inputs.serial }}" USERNAME="${{ inputs.email }}" PASSWORD="${{ inputs.password }}" \
+        docker build --secret id=SERIAL,env=SERIAL --secret id=USERNAME,env=USERNAME --secret id=PASSWORD,env=PASSWORD \
+        -t $CACHED_CONTAINER --build-arg IMAGE=$CONTAINER ${{ github.action_path }}
+      fi
+
+      docker tag $CACHED_CONTAINER ${{ inputs.imageTag }}
     shell: bash
   - name: "Run Unity command."
     uses: act/unity/unity@master