diff --git a/mongoengine/connection.py b/mongoengine/connection.py
index 8aa95daa..4e0c60b0 100644
--- a/mongoengine/connection.py
+++ b/mongoengine/connection.py
@@ -103,7 +103,14 @@ def _get_connection_settings(
         if entity.startswith("mongomock://"):
             conn_settings["is_mock"] = True
             # `mongomock://` is not a valid url prefix and must be replaced by `mongodb://`
-            resolved_hosts.append(entity.replace("mongomock://", "mongodb://", 1))
+            new_entity = entity.replace("mongomock://", "mongodb://", 1)
+            resolved_hosts.append(new_entity)
+
+            uri_dict = uri_parser.parse_uri(new_entity)
+
+            database = uri_dict.get("database")
+            if database:
+                conn_settings["name"] = database
 
         # Handle URI style connections, only updating connection params which
         # were explicitly specified in the URI.
@@ -111,8 +118,9 @@ def _get_connection_settings(
             uri_dict = uri_parser.parse_uri(entity)
             resolved_hosts.append(entity)
 
-            if uri_dict.get("database"):
-                conn_settings["name"] = uri_dict.get("database")
+            database = uri_dict.get("database")
+            if database:
+                conn_settings["name"] = database
 
             for param in ("read_preference", "username", "password"):
                 if uri_dict.get(param):
diff --git a/tests/test_connection.py b/tests/test_connection.py
index f9c9d098..b7dc9268 100644
--- a/tests/test_connection.py
+++ b/tests/test_connection.py
@@ -4,6 +4,8 @@ from pymongo import MongoClient
 from pymongo.errors import OperationFailure, InvalidName
 from pymongo import ReadPreference
 
+from mongoengine import Document
+
 try:
     import unittest2 as unittest
 except ImportError:
@@ -269,6 +271,26 @@ class ConnectionTest(unittest.TestCase):
         conn = get_connection("testdb7")
         self.assertIsInstance(conn, mongomock.MongoClient)
 
+    def test_default_database_with_mocking(self):
+        """Ensure that the default database is correctly set when using mongomock.
+        """
+        try:
+            import mongomock
+        except ImportError:
+            raise SkipTest("you need mongomock installed to run this testcase")
+
+        disconnect_all()
+
+        class SomeDocument(Document):
+            pass
+
+        conn = connect(host="mongomock://localhost:27017/mongoenginetest")
+        some_document = SomeDocument()
+        # database won't exist until we save a document
+        some_document.save()
+        self.assertEqual(conn.get_default_database().name, "mongoenginetest")
+        self.assertEqual(conn.database_names()[0], "mongoenginetest")
+
     def test_connect_with_host_list(self):
         """Ensure that the connect() method works when host is a list