diff --git a/.github/workflows/interop-test.yml b/.github/workflows/interop-test.yml
index c2f07a47453..8fa00f0a8f6 100644
--- a/.github/workflows/interop-test.yml
+++ b/.github/workflows/interop-test.yml
@@ -21,19 +21,12 @@ jobs:
 
       - uses: docker/setup-buildx-action@v3
 
-      # This uses the same S3 cache as all test-plans images. Because we use `cargo-chef` in the Dockerfile, we have a layer available with all dependencies built.
       - name: Build ${{ matrix.flavour }} image
-        run: |
-          docker buildx build \
-            --load \
-            --cache-to   type=s3,mode=max,bucket=libp2p-by-tf-aws-bootstrap,region=us-east-1,prefix=buildCache,name=${{ matrix.flavour }}-rust-libp2p-head \
-            --cache-from type=s3,mode=max,bucket=libp2p-by-tf-aws-bootstrap,region=us-east-1,prefix=buildCache,name=${{ matrix.flavour }}-rust-libp2p-head \
-            -t ${{ matrix.flavour }}-rust-libp2p-head \
-            . \
-            -f interop-tests/Dockerfile.${{ matrix.flavour }}
+        run: ./scripts/build-interop-image.sh
         env:
           AWS_ACCESS_KEY_ID: ${{ vars.TEST_PLANS_BUILD_CACHE_KEY_ID }}
           AWS_SECRET_ACCESS_KEY: ${{ secrets.TEST_PLANS_BUILD_CACHE_KEY }}
+          FLAVOUR: ${{ matrix.flavour }}
 
       - name: Run ${{ matrix.flavour }} tests
         uses: libp2p/test-plans/.github/actions/run-interop-ping-test@master
diff --git a/scripts/build-interop-image.sh b/scripts/build-interop-image.sh
new file mode 100755
index 00000000000..28a8db9188d
--- /dev/null
+++ b/scripts/build-interop-image.sh
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# This uses the same S3 cache as all test-plans images. Because we use `cargo-chef` in the Dockerfile, we have a layer available with all dependencies built.
+
+CACHE_TO=""
+
+# If we have credentials, write to cache
+if [[ -n "${AWS_SECRET_ACCESS_KEY}" ]]; then
+  CACHE_TO="--cache-to   type=s3,mode=max,bucket=libp2p-by-tf-aws-bootstrap,region=us-east-1,prefix=buildCache,name=${FLAVOUR}-rust-libp2p-head"
+fi
+
+docker buildx build \
+  --load \
+  $CACHE_TO \
+  --cache-from type=s3,mode=max,bucket=libp2p-by-tf-aws-bootstrap,region=us-east-1,prefix=buildCache,name=${FLAVOUR}-rust-libp2p-head \
+  -t ${FLAVOUR}-rust-libp2p-head \
+  . \
+  -f interop-tests/Dockerfile.${FLAVOUR}