diff --git a/.github/workflows/cla.yml b/.github/workflows/cla.yml
new file mode 100644
index 0000000..53800df
--- /dev/null
+++ b/.github/workflows/cla.yml
@@ -0,0 +1,10 @@
+name: Scala CLA
+on: [pull_request]
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - run: ./project/scripts/check-cla.sh
+      env:
+        AUTHOR: ${{ github.event.pull_request.user.login }}
diff --git a/project/scripts/check-cla.sh b/project/scripts/check-cla.sh
new file mode 100755
index 0000000..8538a27
--- /dev/null
+++ b/project/scripts/check-cla.sh
@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+set -eux
+
+AUTHOR=$GITHUB_ACTOR
+echo "Pull request submitted by $AUTHOR";
+signed=$(curl -s https://www.lightbend.com/contribute/cla/scala/check/$AUTHOR | jq -r ".signed");
+if [ "$signed" = "true" ] ; then
+  echo "CLA check for $AUTHOR successful";
+else
+  echo "CLA check for $AUTHOR failed";
+  echo "Please sign the Scala CLA to contribute to the Scala compiler.";
+  echo "Go to https://www.lightbend.com/contribute/cla/scala and then";
+  echo "comment on the pull request to ask for a new check.";
+  echo "";
+  echo "Check if CLA is signed: https://www.lightbend.com/contribute/cla/scala/check/$AUTHOR";
+  exit 1;
+fi;