diff --git a/Datastore/src/Query/Query.php b/Datastore/src/Query/Query.php
index 6f67a2d29d82..0d3a62dc595b 100644
--- a/Datastore/src/Query/Query.php
+++ b/Datastore/src/Query/Query.php
@@ -83,6 +83,9 @@ class Query implements QueryInterface
     const OP_GREATER_THAN           = 'GREATER_THAN';
     const OP_GREATER_THAN_OR_EQUAL  = 'GREATER_THAN_OR_EQUAL';
     const OP_EQUALS                 = 'EQUAL';
+    const OP_NOT_EQUALS             = 'NOT_EQUAL';
+    const OP_IN                     = 'IN';
+    const OP_NOT_IN                 = 'NOT_IN';
     const OP_HAS_ANCESTOR           = 'HAS_ANCESTOR';
 
     const ORDER_DEFAULT             = self::ORDER_ASCENDING;
@@ -99,6 +102,9 @@ class Query implements QueryInterface
         self::OP_GREATER_THAN_OR_EQUAL,
         self::OP_EQUALS,
         self::OP_HAS_ANCESTOR,
+        self::OP_NOT_EQUALS,
+        self::OP_IN,
+        self::OP_NOT_IN,
     ];
 
     /**
@@ -109,7 +115,8 @@ class Query implements QueryInterface
         '<=' => self::OP_LESS_THAN_OR_EQUAL,
         '>'  => self::OP_GREATER_THAN,
         '>=' => self::OP_GREATER_THAN_OR_EQUAL,
-        '='  => self::OP_EQUALS
+        '='  => self::OP_EQUALS,
+        '!='  => self::OP_NOT_EQUALS
     ];
 
     /**
@@ -243,7 +250,7 @@ public function kind($kinds)
      *        [here](https://cloud.google.com/datastore/reference/rest/v1/projects/runQuery#operator_1).
      *        Short comparison operators are provided for convenience and are
      *        mapped to their datastore-compatible equivalents. Available short
-     *        operators are `=`, `<`, `<=`, `>`, and `>=`.
+     *        operators are `=`, `!=`, `<`, `<=`, `>`, and `>=`.
      * @param mixed $value The value to check.
      * @return Query
      */
diff --git a/Datastore/tests/Unit/Query/QueryTest.php b/Datastore/tests/Unit/Query/QueryTest.php
index 216347fd087a..de289d9ba90b 100644
--- a/Datastore/tests/Unit/Query/QueryTest.php
+++ b/Datastore/tests/Unit/Query/QueryTest.php
@@ -216,6 +216,33 @@ public function testOperatorConstantsEquals()
         $this->assertEquals('EQUAL', $filters[0]['propertyFilter']['op']);
     }
 
+    public function testOperatorConstantsNotEquals()
+    {
+        $this->query->filter('propName', Query::OP_NOT_EQUALS, 'val');
+        $res = $this->query->queryObject();
+
+        $filters = $res['filter']['compositeFilter']['filters'];
+        $this->assertEquals('NOT_EQUAL', $filters[0]['propertyFilter']['op']);
+    }
+
+    public function testOperatorConstantsIn()
+    {
+        $this->query->filter('propName', Query::OP_IN, 'val');
+        $res = $this->query->queryObject();
+
+        $filters = $res['filter']['compositeFilter']['filters'];
+        $this->assertEquals('IN', $filters[0]['propertyFilter']['op']);
+    }
+
+    public function testOperatorConstantsNotIn()
+    {
+        $this->query->filter('propName', Query::OP_NOT_IN, 'val');
+        $res = $this->query->queryObject();
+
+        $filters = $res['filter']['compositeFilter']['filters'];
+        $this->assertEquals('NOT_IN', $filters[0]['propertyFilter']['op']);
+    }
+
     public function testOperatorConstantsHasAncestor()
     {
         $this->query->filter('propName', Query::OP_HAS_ANCESTOR, 'val');
@@ -270,6 +297,15 @@ public function testShortOperatorEquals()
         $this->assertEquals('EQUAL', $filters[0]['propertyFilter']['op']);
     }
 
+    public function testShortOperatorNotEquals()
+    {
+        $this->query->filter('propName', '!=', 'val');
+        $res = $this->query->queryObject();
+
+        $filters = $res['filter']['compositeFilter']['filters'];
+        $this->assertEquals('NOT_EQUAL', $filters[0]['propertyFilter']['op']);
+    }
+
     public function testOrder()
     {
         $direction = 'DESCENDING';