diff --git a/.github/workflows/aws-upload.yml b/.github/workflows/aws-upload.yml
index 2c738ba..82a3dfb 100644
--- a/.github/workflows/aws-upload.yml
+++ b/.github/workflows/aws-upload.yml
@@ -8,6 +8,16 @@ on:
         required: true
       AWS_S3_CODE_BUCKET:
         required: true
+    inputs:
+      image-tag:
+        description: >
+         An optional value to write into an image_tags file
+         before zipping and uploading the repo contents. The
+         image_tags file is used in some downstream Docker image
+         builds to tag the image with arbitrary values.
+        required: false
+        type: string
+        default: 'no-tags'
 
 jobs:
   upload-to-aws:
@@ -26,9 +36,14 @@ jobs:
         release_name=`echo ${{ github.actor }}-${{ github.ref_name }}`
         echo "Release name: $release_name"
         echo $release_name > release_name
+    - name: Add optional image tags
+      if: inputs.image-tag != 'no-tags'
+      run: |
+        echo "Making an image_tags file with tag value: ${{ inputs.image-tag }}"
+        echo ${{ inputs.image-tag }} > image_tags
     - name: Zip release
       run: |
         echo ${{ github.sha }} > release
         zip -r app.zip .
     - name: Push zip to S3
-      run: aws s3 cp app.zip "s3://${{ secrets.AWS_S3_CODE_BUCKET }}/${{ github.event.repository.name }}.zip"
\ No newline at end of file
+      run: aws s3 cp app.zip "s3://${{ secrets.AWS_S3_CODE_BUCKET }}/${{ github.event.repository.name }}.zip"
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5992878..dd8580b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -35,6 +35,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
     - Check whether project and parent template have diverged
 
 - GitHub Action to validate the reusable workflows themselves
+- Optional `image-tags` input parameter added to the AWS Upload workflow ([#19](https://github.com/arup-group/actions-city-modelling-lab/issues/19))
 
 ### Changed