diff --git a/test/test_platform_pf.py b/test/test_platform_pf.py
index d617cd876..2c4870f9e 100644
--- a/test/test_platform_pf.py
+++ b/test/test_platform_pf.py
@@ -11,5 +11,5 @@ class TestLookup:
             p = tutils.test_data.path("data/pf01")
             d = open(p,"rb").read()
         assert pf.lookup("192.168.1.111", 40000, d) == ("5.5.5.5", 80)
-        assert not pf.lookup("192.168.1.112", 40000, d)
-        assert not pf.lookup("192.168.1.111", 40001, d)
+        tutils.raises("Could not resolve original destination", pf.lookup, "192.168.1.112", 40000, d)
+        tutils.raises("Could not resolve original destination", pf.lookup, "192.168.1.111", 40001, d)
diff --git a/test/test_server.py b/test/test_server.py
index cf50f2805..fea6791da 100644
--- a/test/test_server.py
+++ b/test/test_server.py
@@ -480,7 +480,7 @@ class TestKillResponse(tservers.HTTPProxTest):
 
 class EResolver(tservers.TResolver):
     def original_addr(self, sock):
-        return None
+        raise RuntimeError("Could not resolve original destination.")
 
 
 class TestTransparentResolveError(tservers.TransparentProxTest):