diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 2733f11..f9e15e0 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -99,6 +99,11 @@ jobs:
       STELLAR_NETWORK_PASSPHRASE: "Standalone Network ; February 2017"
       STELLAR_ACCOUNT: default
       STELLAR_CONTRACT_ID: core
+      # The floating `testing` tag moves to new RPC releases, which only
+      # simulate the current and previous protocol. Pin an image that still
+      # simulates the protocol the stellar-cli pin targets; bump it alongside
+      # that pin. Same tag as stellar-scaffold/cli's LOCAL_IMAGE_TAG.
+      QUICKSTART_IMAGE_TAG: v672-b1475.1-testing
     steps:
       - uses: actions/checkout@v6
       - uses: taiki-e/install-action@just
@@ -115,8 +120,8 @@ jobs:
             echo "Could not derive protocol version from stellar-cli pin in Cargo.toml" >&2
             exit 1
           fi
-          echo "Starting local network at protocol $PROTOCOL_VERSION"
-          stellar container start local --protocol-version "$PROTOCOL_VERSION"
+          echo "Starting local network at protocol $PROTOCOL_VERSION with quickstart:$QUICKSTART_IMAGE_TAG"
+          stellar container start local --protocol-version "$PROTOCOL_VERSION" --image-tag-override "$QUICKSTART_IMAGE_TAG"
           echo "Waiting for RPC + friendbot to become healthy..."
           for _ in $(seq 1 50); do
             if curl --no-progress-meter --fail-with-body -X POST "http://localhost:8000/soroban/rpc" \