diff --git a/src/Druid/Query/Aggregation/AbstractAggregationQuery.php b/src/Druid/Query/Aggregation/AbstractAggregationQuery.php
index b1e650f..30a0689 100644
--- a/src/Druid/Query/Aggregation/AbstractAggregationQuery.php
+++ b/src/Druid/Query/Aggregation/AbstractAggregationQuery.php
@@ -35,9 +35,8 @@
 use Druid\Query\Component\FilterInterface;
 use Druid\Query\Component\GranularityInterface;
 use Druid\Query\Component\IntervalInterface;
-use Druid\Query\Component\LimitSpecInterface;
 use Druid\Query\Component\PostAggregatorInterface;
-use Druid\Query\QueryInterface;
+use Druid\Query\Component\StringComponentInterface;
 use JMS\Serializer\Annotation as Serializer;
 
 /**
@@ -55,6 +54,12 @@ abstract class AbstractAggregationQuery extends AbstractQuery
      */
     private $granularity;
 
+    /**
+     * @var GranularityInterface
+     * @Serializer\Exclude
+     */
+    private $granularitySafe;
+
     /**
      * @var array|AggregatorInterface[]
      */
@@ -104,6 +109,28 @@ public function getGranularity()
         return $this->granularity;
     }
 
+    /**
+     * @Serializer\PreSerialize
+     */
+    public function preSerialize()
+    {
+        if ($this->granularity instanceof StringComponentInterface) {
+            $this->granularitySafe = $this->granularity;
+            $this->granularity = (string)$this->granularity;
+        }
+    }
+
+    /**
+     * @Serializer\PostSerialize
+     */
+    public function postSerialize()
+    {
+        if ($this->granularitySafe) {
+            $this->granularity = $this->granularitySafe;
+            $this->granularitySafe = null;
+        }
+    }
+
     /**
      * @param GranularityInterface $granularity
      *
diff --git a/src/Druid/Query/Aggregation/GroupBy.php b/src/Druid/Query/Aggregation/GroupBy.php
index e40c69d..fe3590f 100644
--- a/src/Druid/Query/Aggregation/GroupBy.php
+++ b/src/Druid/Query/Aggregation/GroupBy.php
@@ -29,8 +29,8 @@
 
 namespace Druid\Query\Aggregation;
 
-
 use Druid\Query\Component\DimensionSpecInterface;
+use Druid\Query\Component\Granularity\SimpleGranularity;
 use Druid\Query\Component\HavingInterface;
 use Druid\Query\Component\LimitSpecInterface;
 use Druid\Query\Exception\RequiredArgumentException;
@@ -135,6 +135,9 @@ public function validate()
         if (!$this->getGranularity()) {
             throw new RequiredArgumentException('\'granularity\' is a required parameter');
         }
+        if ($this->getGranularity() instanceof SimpleGranularity && !$this->getGranularity()->getGranularity()) {
+            throw new RequiredArgumentException('invalid \'granularity\' parameter');
+        }
         if (!$this->getIntervals()) {
             throw new RequiredArgumentException('\'intervals\' is a required parameter');
         }
diff --git a/src/Druid/Query/Component/Granularity/SimpleGranularity.php b/src/Druid/Query/Component/Granularity/SimpleGranularity.php
index be9c10a..c9cbceb 100644
--- a/src/Druid/Query/Component/Granularity/SimpleGranularity.php
+++ b/src/Druid/Query/Component/Granularity/SimpleGranularity.php
@@ -31,12 +31,27 @@
 
 use Druid\Query\Component\AbstractTypedComponent;
 use Druid\Query\Component\GranularityInterface;
+use Druid\Query\Component\StringComponentInterface;
 
 /**
  * Class SimpleGranularity.
+ * @link http://druid.io/docs/latest/querying/granularities.html
  */
-class SimpleGranularity extends AbstractTypedComponent implements GranularityInterface
+class SimpleGranularity extends AbstractTypedComponent implements GranularityInterface, StringComponentInterface
 {
+    const ALL = "all";
+    const NONE = "none";
+    const SECOND = "second";
+    const MINUTE = "minute";
+    const FIFTEEN_MINUTE = "fifteen_minute";
+    const THIRTY_MINUTE = "thirty_minute";
+    const HOUR = "hour";
+    const DAY = "day";
+    const WEEK = "week";
+    const MONTH = "month";
+    const QUARTER = "quarter";
+    const YEAR = "year";
+
     /**
      * @var string
      */
@@ -49,9 +64,10 @@ class SimpleGranularity extends AbstractTypedComponent implements GranularityInt
      */
     public function __construct($granularity)
     {
-        $this->granularity = $granularity;
-
-        parent::__construct($granularity);
+        if (defined('self::' . strtoupper($granularity))) {
+            $this->granularity = (string)$granularity;
+        }
+        parent::__construct(self::TYPE_SIMPLE);
     }
 
     /**
@@ -61,4 +77,12 @@ public function getGranularity()
     {
         return $this->granularity;
     }
+
+    /**
+     * @return string
+     */
+    public function __toString()
+    {
+        return (string)$this->granularity;
+    }
 }
diff --git a/src/Druid/Query/Component/GranularityInterface.php b/src/Druid/Query/Component/GranularityInterface.php
index a1b9f50..4803251 100644
--- a/src/Druid/Query/Component/GranularityInterface.php
+++ b/src/Druid/Query/Component/GranularityInterface.php
@@ -34,6 +34,7 @@
  */
 interface GranularityInterface extends TypedInterface, ComponentInterface
 {
+    const TYPE_SIMPLE = 'simple';
     const TYPE_PERIOD = 'period';
     const TYPE_ALL = 'all';
     const TYPE_NONE = 'none';
diff --git a/src/Druid/Query/Component/StringComponentInterface.php b/src/Druid/Query/Component/StringComponentInterface.php
new file mode 100644
index 0000000..9da7b95
--- /dev/null
+++ b/src/Druid/Query/Component/StringComponentInterface.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace Druid\Query\Component;
+
+interface StringComponentInterface
+{
+    /**
+     * @return string
+     */
+    public function __toString();
+}
diff --git a/src/Druid/Query/QueryInterface.php b/src/Druid/Query/QueryInterface.php
index ffb6d85..58cbba2 100644
--- a/src/Druid/Query/QueryInterface.php
+++ b/src/Druid/Query/QueryInterface.php
@@ -29,7 +29,6 @@
 
 namespace Druid\Query;
 
-
 use Druid\Query\Exception\RequiredArgumentException;
 
 /**
diff --git a/src/Druid/QueryBuilder/AbstractAggregationQueryBuilder.php b/src/Druid/QueryBuilder/AbstractAggregationQueryBuilder.php
index b224eb7..2245365 100644
--- a/src/Druid/QueryBuilder/AbstractAggregationQueryBuilder.php
+++ b/src/Druid/QueryBuilder/AbstractAggregationQueryBuilder.php
@@ -31,6 +31,7 @@
 
 use Druid\Query\Component\DataSource\TableDataSource;
 use Druid\Query\Component\DataSourceInterface;
+use Druid\Query\Component\Granularity\SimpleGranularity;
 use Druid\Query\Component\GranularityInterface;
 use Druid\Query\Component\Interval\Interval;
 use Druid\Query\Component\FilterInterface;
@@ -58,13 +59,18 @@ public function setDataSource($dataSource)
     }
 
     /**
-     * @param GranularityInterface $granularity
+     * @param string|GranularityInterface $granularity
      *
      * @return $this
      */
-    public function setGranularity(GranularityInterface $granularity)
+    public function setGranularity($granularity)
     {
-        return $this->addComponent('granularity', $granularity);
+        if ($granularity instanceof GranularityInterface) {
+            return $this->addComponent('granularity', $granularity);
+        } elseif (is_string($granularity)) {
+            return $this->addComponent('granularity', new SimpleGranularity($granularity));
+        }
+        return $this;
     }
 
     /**
diff --git a/src/Druid/QueryBuilder/TopNQueryBuilder.php b/src/Druid/QueryBuilder/TopNQueryBuilder.php
index 4ca4bc0..529ec93 100644
--- a/src/Druid/QueryBuilder/TopNQueryBuilder.php
+++ b/src/Druid/QueryBuilder/TopNQueryBuilder.php
@@ -80,7 +80,10 @@ public function setMetric(MetricInterface $metric)
      */
     public function setThreshold($threshold)
     {
-        return $this->addComponent('threshold', $threshold instanceof ThresholdInterface ? $threshold : new Threshold((int)$threshold));
+        return $this->addComponent(
+            'threshold',
+            $threshold instanceof ThresholdInterface ? $threshold : new Threshold((int)$threshold)
+        );
     }
 
     /**