diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 554e2c119..45d8ffcf4 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -60,6 +60,7 @@ jobs:
       run: |
         eval $(opam env)
         etc/ci_core_tests.sh
+        etc/ci_lean_tests.sh
 
   build-docker:
     runs-on: "ubuntu-latest"
diff --git a/etc/ci_lean_tests.sh b/etc/ci_lean_tests.sh
new file mode 100755
index 000000000..2e1378cb0
--- /dev/null
+++ b/etc/ci_lean_tests.sh
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+set -eu
+
+echo "sail --version: $(sail --version)"
+
+export TEST_PAR=4
+
+test/lean/run_tests.py