diff --git a/src/Jenssegers/Mongodb/Query/Builder.php b/src/Jenssegers/Mongodb/Query/Builder.php
index 8c685de0e..55fb2d4af 100644
--- a/src/Jenssegers/Mongodb/Query/Builder.php
+++ b/src/Jenssegers/Mongodb/Query/Builder.php
@@ -281,17 +281,17 @@ public function distinct($column = false)
      * @param  string  $direction
      * @return Builder
      */
-    public function orderBy($column, $direction = null)
+    public function orderBy($column, $direction = 'asc')
     {
-        if (is_null($direction) && $column == 'natural')
+        $direction = (strtolower($direction) == 'asc' ? 1 : -1);
+
+        if ($column == 'natural')
         {
-            $this->orders['$natural'] = 1;
+            $this->orders['$natural'] = $direction;
         }
         else
         {
-            $direction = $direction ?: 'asc';
-
-            $this->orders[$column] = (strtolower($direction) == 'asc' ? 1 : -1);
+            $this->orders[$column] = $direction;
         }
 
         return $this;
diff --git a/tests/QueryTest.php b/tests/QueryTest.php
index 5975e3c4c..0746dee1f 100644
--- a/tests/QueryTest.php
+++ b/tests/QueryTest.php
@@ -148,8 +148,14 @@ public function testOrder()
 		$user = User::whereNotNull('age')->orderBy('age', 'desc')->first();
 		$this->assertEquals(37, $user->age);
 
-		$user = User::whereNotNull('age')->orderBy('natural')->first();
+		$user = User::whereNotNull('age')->orderBy('natural', 'asc')->first();
 		$this->assertEquals(35, $user->age);
+		
+		$user = User::whereNotNull('age')->orderBy('natural', 'ASC')->first();
+		$this->assertEquals(35, $user->age);
+		
+		$user = User::whereNotNull('age')->orderBy('natural', 'desc')->first();
+		$this->assertEquals(35, $user->age);		
 	}
 
 	public function testGroupBy()