diff --git a/test/property/test_property_filter.py b/test/property/test_property_filter.py
index 66eff3b..8553552 100644
--- a/test/property/test_property_filter.py
+++ b/test/property/test_property_filter.py
@@ -11,7 +11,7 @@ class PropertyFilterTest(TestCase):
         pf = PropertyFilter(pm, "testkey")
         self.assertEqual(pf["testkey"], "testvalue")
 
-    def testMissesPropert(self):
+    def testMissesProperty(self):
         pm = PropertyLayer()
         pm["testkey"] = "testvalue"
         pf = PropertyFilter(pm, "other_key")
@@ -49,3 +49,11 @@ class PropertyFilterTest(TestCase):
         pf["testkey"] = "new value"
         self.assertEqual(pm["testkey"], "new value")
         self.assertEqual(pf["testkey"], "new value")
+
+    def testRejectsWrite(self):
+        pm = PropertyLayer()
+        pm["testkey"] = "old value"
+        pf = PropertyFilter(pm, "otherkey")
+        with self.assertRaises(KeyError):
+            pf["testkey"] = "new value"
+        self.assertEqual(pm["testkey"], "old value")