diff --git a/homeassistant/components/lock/significant_change.py b/homeassistant/components/lock/significant_change.py
new file mode 100644
index 00000000000..59a3b1a95c5
--- /dev/null
+++ b/homeassistant/components/lock/significant_change.py
@@ -0,0 +1,20 @@
+"""Helper to test significant Lock state changes."""
+from typing import Any, Optional
+
+from homeassistant.core import HomeAssistant, callback
+
+
+@callback
+def async_check_significant_change(
+    hass: HomeAssistant,
+    old_state: str,
+    old_attrs: dict,
+    new_state: str,
+    new_attrs: dict,
+    **kwargs: Any,
+) -> Optional[bool]:
+    """Test if state significantly changed."""
+    if old_state != new_state:
+        return True
+
+    return False
diff --git a/tests/components/lock/test_significant_change.py b/tests/components/lock/test_significant_change.py
new file mode 100644
index 00000000000..a9ffbc0d1c4
--- /dev/null
+++ b/tests/components/lock/test_significant_change.py
@@ -0,0 +1,23 @@
+"""Test the Lock significant change platform."""
+from homeassistant.components.lock.significant_change import (
+    async_check_significant_change,
+)
+
+
+async def test_significant_change():
+    """Detect Lock significant changes."""
+    old_attrs = {"attr_1": "a"}
+    new_attrs = {"attr_1": "b"}
+
+    assert (
+        async_check_significant_change(None, "locked", old_attrs, "locked", old_attrs)
+        is False
+    )
+    assert (
+        async_check_significant_change(None, "locked", old_attrs, "locked", new_attrs)
+        is False
+    )
+    assert (
+        async_check_significant_change(None, "locked", old_attrs, "unlocked", old_attrs)
+        is True
+    )