diff --git a/scripts/release.sh b/scripts/release.sh
index 091abf87f..e14ba04a7 100755
--- a/scripts/release.sh
+++ b/scripts/release.sh
@@ -25,6 +25,14 @@ if ! [[ -v KOKORO_RELEASE_TAG ]]; then
   echo "No KOKORO_RELEASE_TAG provided." >&2
   exit 1
 fi
+if ! [[ -v KOKORO_RELNOTES ]]; then
+  echo "No KOKORO_RELNOTES provided." >&2
+  exit 1
+fi
+if ! [[ -r "${KOKORO_ARTIFACTS_DIR}/${KOKORO_RELNOTES}" ]]; then
+  echo "The file '${KOKORO_ARTIFACTS_DIR}/${KOKORO_RELNOTES}' is not readable." >&2
+  exit 1
+fi
 
 # Unless an explicit releaser is provided, use the bot e-mail.
 declare -r KOKORO_RELEASE_AUTHOR=${KOKORO_RELEASE_AUTHOR:-gvisor-bot}
@@ -46,4 +54,7 @@ EOF
 fi
 
 # Run the release tool, which pushes to the origin repository.
-tools/tag_release.sh "${KOKORO_RELEASE_COMMIT}" "${KOKORO_RELEASE_TAG}"
+tools/tag_release.sh \
+    "${KOKORO_RELEASE_COMMIT}" \
+    "${KOKORO_RELEASE_TAG}" \
+    "${KOKORO_ARTIFACTS_DIR}/${KOKORO_RELNOTES}"
diff --git a/tools/tag_release.sh b/tools/tag_release.sh
index f33b902d6..4dbfe420a 100755
--- a/tools/tag_release.sh
+++ b/tools/tag_release.sh
@@ -21,13 +21,19 @@
 set -xeu
 
 # Check arguments.
-if [ "$#" -ne 2 ]; then
-  echo "usage: $0 <commit|revid> <release.rc>"
+if [ "$#" -ne 3 ]; then
+  echo "usage: $0 <commit|revid> <release.rc> <message-file>"
   exit 1
 fi
 
 declare -r target_commit="$1"
 declare -r release="$2"
+declare -r message_file="$3"
+
+if ! [[ -r "${message_file}" ]]; then
+  echo "error: message file '${message_file}' is not readable."
+  exit 1
+fi
 
 closest_commit() {
   while read line; do
@@ -64,6 +70,6 @@ fi
 
 # Tag the given commit (annotated, to record the committer).
 declare -r tag="release-${release}"
-(git tag -m "Release ${release}" -a "${tag}" "${commit}" && \
+(git tag -F "${message_file}" -a "${tag}" "${commit}" && \
   git push origin tag "${tag}") || \
   (git tag -d "${tag}" && false)