diff --git a/tests/test_merge_policy.py b/tests/test_merge_policy.py
new file mode 100644
index 0000000..fb9a632
--- /dev/null
+++ b/tests/test_merge_policy.py
@@ -0,0 +1,20 @@
+"""Tests for merge-policy gates."""
+
+from ai_agent.domain.merge_policy import may_merge
+from ai_agent.domain.platform import MergePolicy
+
+
+def test_may_merge_rejects_exhausted_daily_budget() -> None:
+    policy = MergePolicy(max_merges_per_day=2)
+
+    allowed, reason = may_merge(
+        policy,
+        ci_green=True,
+        diff_lines=1,
+        changed_paths=["tests/test_merge_policy.py"],
+        merges_today=2,
+        stopped=False,
+    )
+
+    assert not allowed
+    assert reason == "daily merge budget exhausted"