diff --git a/frigate/test/test_motion_detector.py b/frigate/test/test_motion_detector.py
new file mode 100644
index 000000000..8dd2cdfaa
--- /dev/null
+++ b/frigate/test/test_motion_detector.py
@@ -0,0 +1,91 @@
+import unittest
+
+import numpy as np
+
+from frigate.config.camera.motion import MotionConfig
+from frigate.motion.improved_motion import ImprovedMotionDetector
+
+
+class TestImprovedMotionDetector(unittest.TestCase):
+    def setUp(self):
+        # small frame for testing; actual frames are grayscale
+        self.frame_shape = (100, 100)  # height, width
+        self.config = MotionConfig()
+        # motion detector assumes a rasterized_mask attribute exists on config
+        # when update_mask() is called; add one manually by bypassing pydantic.
+        object.__setattr__(
+            self.config,
+            "rasterized_mask",
+            np.ones((self.frame_shape[0], self.frame_shape[1]), dtype=np.uint8),
+        )
+
+        # create minimal PTZ metrics stub to satisfy detector checks
+        class _Stub:
+            def __init__(self, value=False):
+                self.value = value
+
+            def is_set(self):
+                return bool(self.value)
+
+        class DummyPTZ:
+            def __init__(self):
+                self.autotracker_enabled = _Stub(False)
+                self.motor_stopped = _Stub(False)
+                self.stop_time = _Stub(0)
+
+        self.detector = ImprovedMotionDetector(
+            self.frame_shape, self.config, fps=30, ptz_metrics=DummyPTZ()
+        )
+
+        # establish a baseline frame (all zeros)
+        base_frame = np.zeros(
+            (self.frame_shape[0], self.frame_shape[1]), dtype=np.uint8
+        )
+        self.detector.detect(base_frame)
+
+    def _half_change_frame(self) -> np.ndarray:
+        """Produce a frame where roughly half of the pixels are different."""
+        frame = np.zeros((self.frame_shape[0], self.frame_shape[1]), dtype=np.uint8)
+        # flip the top half to white
+        frame[: self.frame_shape[0] // 2, :] = 255
+        return frame
+
+    def test_skip_motion_threshold_default(self):
+        """With the default (1.0) setting, motion should still be reported."""
+        frame = self._half_change_frame()
+        boxes = self.detector.detect(frame)
+        self.assertTrue(
+            boxes, "Expected motion boxes when skip threshold is at default"
+        )
+
+    def test_skip_motion_threshold_applied(self):
+        """Setting a low skip threshold should prevent any boxes from being returned."""
+        # change the config and update the detector reference
+        self.config.skip_motion_threshold = 0.4
+        self.detector.config = self.config
+        self.detector.update_mask()
+
+        frame = self._half_change_frame()
+        boxes = self.detector.detect(frame)
+        self.assertEqual(
+            boxes,
+            [],
+            "Motion boxes should be empty when scene change exceeds skip threshold",
+        )
+
+    def test_skip_motion_threshold_does_not_affect_calibration(self):
+        """Even when skipping, the detector should go into calibrating state."""
+        self.config.skip_motion_threshold = 0.4
+        self.detector.config = self.config
+        self.detector.update_mask()
+
+        frame = self._half_change_frame()
+        _ = self.detector.detect(frame)
+        self.assertTrue(
+            self.detector.calibrating,
+            "Detector should be in calibrating state after skip event",
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()