diff --git a/csp_advanced/tests.py b/csp_advanced/tests.py
index 9002a4a..80ab2fc 100644
--- a/csp_advanced/tests.py
+++ b/csp_advanced/tests.py
@@ -3,6 +3,7 @@ from collections import OrderedDict
 from django.test import SimpleTestCase
 
 from csp import CSPCompiler, InvalidCSPError
+from utils import callable_csp_dict, merge_csp_dict
 
 
 class CSPCompileTest(SimpleTestCase):
@@ -73,3 +74,48 @@ class CSPCompileTest(SimpleTestCase):
             "style-src 'self'; script-src 'self' https://dmoj.ca; frame-src 'none'; "
             "plugin-types application/pdf; block-all-mixed-content; sandbox allow-scripts; "
             "report-uri /dev/null")
+
+
+class CallableCSPDictTest(SimpleTestCase):
+    def test_callable(self):
+        self.assertEqual(callable_csp_dict(lambda: {'key': 'value'}), {'key': 'value'})
+
+    def test_normal_dict(self):
+        self.assertEqual(callable_csp_dict({'key': 'value'}), {'key': 'value'})
+
+    def test_callable_entry(self):
+        self.assertEqual(callable_csp_dict({'key': lambda: 'value'}), {'key': 'value'})
+
+    def test_mixed_entry(self):
+        self.assertEqual(callable_csp_dict({
+            'key': lambda: 'value',
+            'name': 'mixed',
+        }), {
+            'key': 'value',
+            'name': 'mixed'
+        })
+
+
+class MergeCSPDictTest(SimpleTestCase):
+    def test_null(self):
+        test = {'key': 'value'}
+        self.assertEqual(merge_csp_dict(test, {}), test)
+
+    def test_distinct_key(self):
+        self.assertEqual(merge_csp_dict({'spam': 1}, {'ham': 2}), {'spam': 1, 'ham': 2})
+
+    def test_scalar_override(self):
+        self.assertEqual(merge_csp_dict({'spam': 1}, {'spam': 2}), {'spam': 2})
+
+    def test_list_override(self):
+        orig = [1]
+        self.assertEqual(merge_csp_dict({'spam': orig}, {'spam': [2]}), {'spam': [1, 2]})
+        self.assertEqual(orig, [1])
+
+    def test_set_override(self):
+        orig = {1}
+        self.assertEqual(merge_csp_dict({'spam': orig}, {'spam': [2]}), {'spam': {1, 2}})
+        self.assertEqual(orig, {1})
+
+    def test_tuple_override(self):
+        self.assertEqual(merge_csp_dict({'spam': (1,)}, {'spam': (2,)}), {'spam': (1, 2)})
diff --git a/csp_advanced/utils.py b/csp_advanced/utils.py
new file mode 100644
index 0000000..49590d3
--- /dev/null
+++ b/csp_advanced/utils.py
@@ -0,0 +1,34 @@
+def callable_csp_dict(data):
+    if callable(data):
+        return data()
+    result = {}
+    for key, value in data.iteritems():
+        if callable(value):
+            result[key] = value()
+        else:
+            result[key] = value
+    return result
+
+
+def merge_csp_dict(template, override):
+    result = template.copy()
+    for key, value in override.iteritems():
+        if key not in result:
+            result[key] = value
+            continue
+        orig = result[key]
+        if isinstance(orig, list):
+            if orig == template[key]:
+                result[key] = orig + list(value)
+            else:
+                orig += value
+        elif isinstance(orig, set):
+            if orig == template[key]:
+                result[key] = orig.union(value)
+            else:
+                orig.update(value)
+        elif isinstance(orig, tuple):
+            result[key] = orig + tuple(value)
+        else:
+            result[key] = value
+    return result