diff --git a/tests/unit/test_matchers.py b/tests/unit/test_matchers.py
index 30ab5ff..ae29c8a 100644
--- a/tests/unit/test_matchers.py
+++ b/tests/unit/test_matchers.py
@@ -20,7 +20,7 @@ def assert_matcher(matcher_name):
     matcher = getattr(matchers, matcher_name)
     for k1, k2 in itertools.permutations(REQUESTS, 2):
         matched = matcher(REQUESTS[k1], REQUESTS[k2])
-        if matcher_name in {k1, k2}:
+        if matcher_name in set((k1, k2)):
             assert not matched
         else:
             assert matched
@@ -29,7 +29,7 @@ def assert_matcher(matcher_name):
 def test_url_matcher():
     for k1, k2 in itertools.permutations(REQUESTS, 2):
         matched = matchers.url(REQUESTS[k1], REQUESTS[k2])
-        if {k1, k2} != {'base', 'method'}:
+        if set((k1, k2)) != set(('base', 'method')):
             assert not matched
         else:
             assert matched