diff --git a/third_party/update-marl.sh b/third_party/update-marl.sh
new file mode 100755
index 0000000..0750b9a
--- /dev/null
+++ b/third_party/update-marl.sh
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# update-marl merges the latest changes from the github.com/google/marl into
+# third_party/marl. This script copies the change descriptions from the squash
+# change into the top merge change, along with a standardized description.
+REASON=$1
+
+if [ ! -z "$REASON" ]; then
+  REASON="\n$REASON\n"
+fi
+
+git subtree pull --prefix third_party/marl https://github.com/google/marl master --squash -m "Update marl"
+
+ALL_CHANGES=`git log -n 1 HEAD^2 | egrep '^(\s{4}[0-9a-f]{9}\s*.*)$'`
+HEAD_CHANGE=`echo "$ALL_CHANGES" | egrep '[0-9a-f]{9}' -o -m 1`
+LOG_MSG=`echo -e "Update Marl to $HEAD_CHANGE\n${REASON}\nChanges:\n$ALL_CHANGES\n\nCommands:\n    git subtree pull --prefix third_party/marl https://github.com/google/marl master --squash\n\nBug: b/140546382"`
+git commit --amend -m "$LOG_MSG"
\ No newline at end of file