diff --git a/extensions/mongo/Connection.php b/extensions/mongo/Connection.php
index ce99ee4..725c757 100644
--- a/extensions/mongo/Connection.php
+++ b/extensions/mongo/Connection.php
@@ -85,7 +85,9 @@ class Connection extends Component
 	protected function fetchDefaultDatabaseName()
 	{
 		if ($this->defaultDatabaseName === null) {
-			if (preg_match('/^mongodb:\\/\\/.+\\/(.+)$/s', $this->dsn, $matches)) {
+			if (isset($this->options['db'])) {
+				$this->defaultDatabaseName = $this->options['db'];
+			} elseif (preg_match('/^mongodb:\\/\\/.+\\/(.+)$/s', $this->dsn, $matches)) {
 				$this->defaultDatabaseName = $matches[1];
 			} else {
 				throw new InvalidConfigException("Unable to determine default database name from dsn.");
diff --git a/tests/unit/extensions/mongo/ConnectionTest.php b/tests/unit/extensions/mongo/ConnectionTest.php
index 3b8a1a2..b3252b9 100644
--- a/tests/unit/extensions/mongo/ConnectionTest.php
+++ b/tests/unit/extensions/mongo/ConnectionTest.php
@@ -71,6 +71,12 @@ class ConnectionTest extends MongoTestCase
 		$this->assertTrue($database instanceof Database, 'Unable to get default database!');
 
 		$connection = new Connection();
+		$connection->dsn = $this->mongoConfig['dsn'];
+		$connection->options = ['db' => $this->mongoConfig['defaultDatabaseName']];
+		$database = $connection->getDatabase();
+		$this->assertTrue($database instanceof Database, 'Unable to determine default database from options!');
+
+		$connection = new Connection();
 		$connection->dsn = $this->mongoConfig['dsn'] . '/' . $this->mongoConfig['defaultDatabaseName'];
 		$database = $connection->getDatabase();
 		$this->assertTrue($database instanceof Database, 'Unable to determine default database from dsn!');
diff --git a/tests/unit/extensions/mongo/MongoTestCase.php b/tests/unit/extensions/mongo/MongoTestCase.php
index 439afb2..0bdcd74 100644
--- a/tests/unit/extensions/mongo/MongoTestCase.php
+++ b/tests/unit/extensions/mongo/MongoTestCase.php
@@ -77,9 +77,7 @@ class MongoTestCase extends TestCase
 		}
 		$db = new Connection;
 		$db->dsn = $this->mongoConfig['dsn'];
-		if (isset($this->mongoConfig['defaultDatabaseName'])) {
-			$db->defaultDatabaseName = $this->mongoConfig['defaultDatabaseName'];
-		}
+		$db->defaultDatabaseName = $this->mongoConfig['defaultDatabaseName'];
 		if (isset($this->mongoConfig['options'])) {
 			$db->options = $this->mongoConfig['options'];
 		}