diff --git a/tests/test_raw_frameset.py b/tests/test_raw_frameset.py
index e077bf5..141d7f4 100644
--- a/tests/test_raw_frameset.py
+++ b/tests/test_raw_frameset.py
@@ -42,6 +42,9 @@ def client():
     cam = RealSenseD435()
     open_fake_camera(cam, FakePipeline(fps=30), FakeAlign(delay_s=0.0))
     _identity_calibration(cam)
+    # Each fake camera numbers its framesets from 1: start from empty shared-encoding caches.
+    routes._encoded_colors.clear()
+    routes._encoded_raws.clear()
     routes.set_camera(cam)
     websocket.set_camera(cam)
     yield TestClient(app)