diff --git a/extensions/mongo/Collection.php b/extensions/mongo/Collection.php
index e92480b..64242c1 100644
--- a/extensions/mongo/Collection.php
+++ b/extensions/mongo/Collection.php
@@ -165,7 +165,7 @@ class Collection extends Object
 		try {
 			$result = $this->mongoCollection->deleteIndexes();
 			$this->tryResultError($result);
-			return $result['nIndexesWas'] - 1;
+			return $result['nIndexesWas'];
 		} catch (\Exception $e) {
 			Yii::endProfile($token, __METHOD__);
 			throw new Exception($e->getMessage(), (int)$e->getCode(), $e);
diff --git a/tests/unit/extensions/mongo/CollectionTest.php b/tests/unit/extensions/mongo/CollectionTest.php
index 4bce0fa..bc13b2e 100644
--- a/tests/unit/extensions/mongo/CollectionTest.php
+++ b/tests/unit/extensions/mongo/CollectionTest.php
@@ -270,7 +270,7 @@ class CollectionTest extends MongoTestCase
 	{
 		$collection = $this->getConnection()->getCollection('customer');
 		$collection->createIndex('name');
-		$this->assertEquals(1, $collection->dropAllIndexes());
+		$this->assertEquals(2, $collection->dropAllIndexes());
 		$indexInfo = $collection->mongoCollection->getIndexInfo();
 		$this->assertEquals(1, count($indexInfo));
 	}