diff --git a/tools/actions/merge.sh b/tools/actions/merge.sh
index 45947f64c2a4db..b151000275ee2b 100755
--- a/tools/actions/merge.sh
+++ b/tools/actions/merge.sh
@@ -48,7 +48,7 @@ fi
 
 git log -1 HEAD  --pretty='format:%B' | git interpret-trailers --parse --no-divider | \
   grep -q -x "^PR-URL: https://github.com/$OWNER/$REPOSITORY/pull/$pr$" || {
-    echo "Invalid PR-URL trailer"
+    echo "Invalid PR-URL trailer - have you run 'git node land' to add it?"
     exit 1
   }
 git log -1 HEAD^ --pretty='format:%B' | git interpret-trailers --parse --no-divider | \
@@ -56,6 +56,11 @@ git log -1 HEAD^ --pretty='format:%B' | git interpret-trailers --parse --no-divi
     echo "Refuse to squash and merge a PR landing in more than one commit"
     exit 1
   }
+git log -1 HEAD  --pretty='format:%B' | git interpret-trailers --parse --no-divider | \
+  grep -q "^Reviewed-By: " || {
+    echo "No Reviewed-By: lines in the commit message - have you run 'git node land' to add them?"
+    exit 1
+  }
 
 commit_title=$(git log -1 --pretty='format:%s')
 commit_body=$(git log -1 --pretty='format:%b')