diff --git a/tests/kokoro/gcp_ubuntu/build.sh b/tests/kokoro/gcp_ubuntu/build.sh
index 93c2467..555b845 100755
--- a/tests/kokoro/gcp_ubuntu/build.sh
+++ b/tests/kokoro/gcp_ubuntu/build.sh
@@ -42,4 +42,4 @@
   --env REACTOR_BACKEND=$REACTOR_BACKEND \
   --env LLVM_VERSION=$LLVM_VERSION \
   --entrypoint "${SCRIPT_DIR}/docker.sh" \
-  "gcr.io/shaderc-build/radial-build:latest"
+  us-east4-docker.pkg.dev/shaderc-build/radial-docker/ubuntu-24.04-amd64/cpp-builder
diff --git a/tests/kokoro/gcp_ubuntu/docker.sh b/tests/kokoro/gcp_ubuntu/docker.sh
index b69d5da..43fc9e2 100755
--- a/tests/kokoro/gcp_ubuntu/docker.sh
+++ b/tests/kokoro/gcp_ubuntu/docker.sh
@@ -48,9 +48,17 @@
 
 status "Cloning to clean source directory at '${SRC_DIR}'"
 
+set -x
+# The source git repo was created in the host environment (outside
+# docker) and is owned by a different user than the one running
+# inside the docker container.  Tell git to bypass the ownership
+# check: it's ok to read and operate on the repo.
+git config --global --add safe.directory '*'
+
 mkdir -p ${SRC_DIR}
 cd ${SRC_DIR}
 git clone ${CLONE_SRC_DIR} .
+set +x
 
 mkdir -p build && cd build