diff --git a/script/release-binary b/script/release-binary
index bf83a7d3115..61d446533b8 100755
--- a/script/release-binary
+++ b/script/release-binary
@@ -19,24 +19,29 @@
 set -ex
 
 # Make sure to this script on x86_64 Ubuntu Xenial
+UBUNTU_RELEASE="$(lsb_release -c -s)"
+[[ "${UBUNTU_RELEASE}" == 'xenial' ]] || { echo 'must run on Ubuntu Xenial'; exit 1; }
 
 # The bucket name to store proxy binary
-BUCKET_NAME="istio-build/proxy"
+DST="gs://istio-build/proxy"
 
 # The proxy binary name.
 SHA="$(git rev-parse --verify HEAD)"
 BINARY_NAME="envoy-alpha-${SHA}.tar.gz"
 SHA256_NAME="envoy-alpha-${SHA}.sha256"
 
+# If binary already exists skip.
+gsutil stat "${DST}/${BINARY_NAME}" \
+  && { echo 'Binary already exists'; exit 0; } \
+  || echo 'Building a new binary.'
+
 # Build the binary
 bazel build --config=release //src/envoy/mixer:envoy_tar
 BAZEL_TARGET="bazel-bin/src/envoy/mixer/envoy_tar.tar.gz"
 ln "${BAZEL_TARGET}" "${BINARY_NAME}"
 sha256sum "${BINARY_NAME}" > "${SHA256_NAME}"
-DST="gs://${BUCKET_NAME}/"
 
 # Copy it to the bucket.
-echo "Copying ${BINARY_NAME} ${SHA256_NAME} to ${DST}"
-gsutil cp "${BINARY_NAME}" "${SHA256_NAME}" "${DST}"
-
+echo "Copying ${BINARY_NAME} ${SHA256_NAME} to ${DST}/"
+gsutil cp "${BINARY_NAME}" "${SHA256_NAME}" "${DST}/"
 
diff --git a/src/envoy/mixer/repositories.bzl b/src/envoy/mixer/repositories.bzl
index d5dfe4ac19c..1ec26f2a47c 100644
--- a/src/envoy/mixer/repositories.bzl
+++ b/src/envoy/mixer/repositories.bzl
@@ -15,10 +15,12 @@
 ################################################################################
 #
 
+MIXER_CLIENT = "7b8544d765f9d7d86d28770c8d27d69cbf9509ac"
+
 def mixer_client_repositories(bind=True):
     native.git_repository(
         name = "mixerclient_git",
-        commit = "7b8544d765f9d7d86d28770c8d27d69cbf9509ac",
+        commit = MIXER_CLIENT,
         remote = "https://github.com/istio/mixerclient.git",
     )