diff --git a/jsonschema/_validators.py b/jsonschema/_validators.py
index 4b45785..d0baec8 100644
--- a/jsonschema/_validators.py
+++ b/jsonschema/_validators.py
@@ -30,13 +30,16 @@ def additionalProperties(validator, aP, instance, schema):
                 yield error
     elif not aP and extras:
         if "patternProperties" in schema:
-            patterns = sorted(schema["patternProperties"].keys())
+            patterns = sorted(schema["patternProperties"])
             if len(extras) == 1:
                 verb = "does"
             else:
                 verb = "do"
-            error = "%s %s not match any of the regexs: %s" % (
-                ", ".join(map(repr, sorted(extras))), verb, ", ".join(patterns))
+            error = "%s %s not match any of the regexes: %s" % (
+                ", ".join(map(repr, sorted(extras))),
+                verb,
+                ", ".join(map(repr, patterns)),
+            )
             yield ValidationError(error)
         else:
             error = "Additional properties are not allowed (%s %s unexpected)"
diff --git a/jsonschema/tests/test_validators.py b/jsonschema/tests/test_validators.py
index 432702f..fb59b83 100644
--- a/jsonschema/tests/test_validators.py
+++ b/jsonschema/tests/test_validators.py
@@ -195,21 +195,25 @@ class TestValidationErrorMessages(unittest.TestCase):
         schema = {u"type": u"object",
                   u"additionalProperties": False,
                   u"patternProperties": {
-                      u"$abc^": {u"type": u"string"},
-                      u"$def^": {u"type": u"string"}
+                      u"^abc$": {u"type": u"string"},
+                      u"^def$": {u"type": u"string"}
                   }}
         message = self.message_for({u"zebra": 123}, schema,
                                    cls=Draft4Validator)
         self.assertEqual(
             message,
-            "{} does not match any of the regexs: $abc^, $def^".format(
-                repr(u"zebra")))
+            "{} does not match any of the regexes: {}, {}".format(
+                repr(u"zebra"), repr(u"^abc$"), repr(u"^def$"),
+            ),
+        )
         message = self.message_for({u"zebra": 123, u"fish": 456}, schema,
                                    cls=Draft4Validator)
         self.assertEqual(
             message,
-            "{}, {} do not match any of the regexs: $abc^, $def^".format(
-                repr(u"fish"), repr(u"zebra")))
+            "{}, {} do not match any of the regexes: {}, {}".format(
+                repr(u"fish"), repr(u"zebra"), repr(u"^abc$"), repr(u"^def$")
+            ),
+        )
 
 
 class TestValidationErrorDetails(unittest.TestCase):