diff --git a/test/test_health_monitor.py b/test/test_health_monitor.py
index f8427476..41a6206a 100644
--- a/test/test_health_monitor.py
+++ b/test/test_health_monitor.py
@@ -280,9 +280,11 @@ class TestGetRecoverySuggestions:
 class TestMonitorLifecycle:
     def test_start_monitoring(self, monitor):
         monitor.start_monitoring()
-        assert monitor._monitor_thread is not None
-        assert monitor._monitor_thread.is_alive()
-        monitor.stop_monitoring()
+        try:
+            assert monitor._monitor_thread is not None
+            assert monitor._monitor_thread.is_alive()
+        finally:
+            monitor.stop_monitoring()
 
     def test_stop_monitoring(self, monitor):
         monitor.start_monitoring()
@@ -292,10 +294,12 @@ class TestMonitorLifecycle:
 
     def test_double_start_no_duplicate_threads(self, monitor):
         monitor.start_monitoring()
-        thread1 = monitor._monitor_thread
-        monitor.start_monitoring()  # should be idempotent
-        assert monitor._monitor_thread is thread1
-        monitor.stop_monitoring()
+        try:
+            thread1 = monitor._monitor_thread
+            monitor.start_monitoring()  # should be idempotent
+            assert monitor._monitor_thread is thread1
+        finally:
+            monitor.stop_monitoring()
 
     def test_register_health_check(self, monitor):
         callback = MagicMock()
diff --git a/test/test_scroll_helper.py b/test/test_scroll_helper.py
index 30e76b9c..517d3e47 100644
--- a/test/test_scroll_helper.py
+++ b/test/test_scroll_helper.py
@@ -224,7 +224,7 @@ class TestCalculateDynamicDuration:
         assert result >= 60
 
     def test_respects_max_duration(self, helper):
-        helper.create_scrolling_image([_make_image(width=50000)])
+        helper.create_scrolling_image([_make_image(width=5000)])
         helper.min_duration = 10
         helper.max_duration = 60
         helper.scroll_speed = 1.0  # very slow → very long time