diff --git a/exchange/cache.py b/exchange/cache.py
index eff210d..996a67f 100644
--- a/exchange/cache.py
+++ b/exchange/cache.py
@@ -31,8 +31,10 @@ def _get_cache_key(source_currency, target_currency):
 
 def update_rates_cached():
     rates = ExchangeRate.objects.all()
-    cache_map = {_get_cache_key(rate.source.code, rate.target.code): rate.rate
-                 for rate in rates}
+    cache_map = dict(
+        ((_get_cache_key(rate.source.code, rate.target.code), rate.rate)
+         for rate in rates)
+    )
     cache.set_many(cache_map, timeout=CACHE_TIMEOUT)
     local_cache.clear()
     return cache_map
@@ -49,6 +51,6 @@ def get_rate_cached(source_currency, target_currency):
 
 
 def get_rates_cached(args_list):
-    key_map = {_get_cache_key(*args): args for args in args_list}
+    key_map = dict(((_get_cache_key(*args), args) for args in args_list))
     cache_map = cache.get_many(key_map.keys())
-    return {key_map[key]: cache_map.get(key) for key in key_map.keys()}
+    return dict(((key_map[key], cache_map.get(key)) for key in key_map.keys()))
diff --git a/exchange/conversion.py b/exchange/conversion.py
index 400cbd8..ebfb057 100644
--- a/exchange/conversion.py
+++ b/exchange/conversion.py
@@ -61,16 +61,16 @@ def get_rates(currencies):
                 sources.append(source)
                 targets.append(target)
     else:
-        rate_map = {c: None for c in currencies}
+        rate_map = dict(((c, None) for c in currencies))
         sources = map(itemgetter(0), currencies)
         targets = map(itemgetter(1), currencies)
 
     rates = ExchangeRate.objects.filter(
         source__code__in=sources,
         target__code__in=targets).values_list(
-        'source__code',
-        'target__code',
-        'rate')
+            'source__code',
+            'target__code',
+            'rate')
 
     for source, target, rate in rates:
         key = (source, target)
diff --git a/test_project/settings.py b/test_project/settings.py
index 2beb02d..ddfa060 100644
--- a/test_project/settings.py
+++ b/test_project/settings.py
@@ -10,3 +10,5 @@
 TEST_RUNNER = 'django_nose.NoseTestSuiteRunner'
 
 OPENEXCHANGERATES_API_KEY = '<DUMMY_KEY>'
+
+SECRET_KEY = '<DummySecret>'