diff --git a/UPGRADE-1.3.md b/UPGRADE-1.3.md
index 0188a73f50..38451af0da 100644
--- a/UPGRADE-1.3.md
+++ b/UPGRADE-1.3.md
@@ -50,6 +50,9 @@ in favor of `Doctrine\ODM\MongoDB\Mapping\ClassMetadata` and will be dropped in
  * Using more than one class-level document annotation (e.g. `@Document`,
    `@MappedSuperclass`) is deprecated and will throw an exception in 2.0.
    Classes should only be annotated with a single document annotation.
+ * The `dropDups` option on the `@Index` annotation was deprecated and will be 
+   dropped without replacement in 2.0. This functionality is no longer
+   available.
 
 ### XML mappings
 
@@ -57,6 +60,9 @@ in favor of `Doctrine\ODM\MongoDB\Mapping\ClassMetadata` and will be dropped in
    will be dropped in 2.0. Use `write-concern` instead.
  * The `fieldName` attribute in field mappings has been deprecated and will be
    dropped in 2.0. Use `field-name` instead.
+ * The `drop-dups` attribute in the `index` element was deprecated and will be
+   dropped without replacement in 2.0. This functionality is no longer
+   available.
    
 ### Full discriminator maps required
 
diff --git a/docs/en/reference/indexes.rst b/docs/en/reference/indexes.rst
index 52534f310c..569932c0eb 100644
--- a/docs/en/reference/indexes.rst
+++ b/docs/en/reference/indexes.rst
@@ -49,7 +49,8 @@ You can customize the index with some additional options:
    too long.
 - 
    **dropDups** - If a unique index is being created and duplicate
-   values exist, drop all but one duplicate value.
+   values exist, drop all but one duplicate value. This option is deprecated and
+   will be dropped without replacement in 2.0.
 - 
    **background** - Create indexes in the background while other
    operations are taking place. By default, index creation happens
diff --git a/doctrine-mongo-mapping.xsd b/doctrine-mongo-mapping.xsd
index f6d476ffc2..20564a547f 100644
--- a/doctrine-mongo-mapping.xsd
+++ b/doctrine-mongo-mapping.xsd
@@ -377,6 +377,7 @@
       <xs:element name="partial-filter-expression" type="odm:partial-filter-expression" minOccurs="0" maxOccurs="1"/>
     </xs:choice>
     <xs:attribute name="name" type="xs:NMTOKEN"/>
+    <!-- deprecated -->
     <xs:attribute name="drop-dups" type="xs:boolean"/>
     <xs:attribute name="background" type="xs:boolean"/>
     <xs:attribute name="safe" type="xs:boolean"/>
diff --git a/lib/Doctrine/ODM/MongoDB/Mapping/Annotations/AbstractIndex.php b/lib/Doctrine/ODM/MongoDB/Mapping/Annotations/AbstractIndex.php
index 4155be06b6..089cdab8dc 100644
--- a/lib/Doctrine/ODM/MongoDB/Mapping/Annotations/AbstractIndex.php
+++ b/lib/Doctrine/ODM/MongoDB/Mapping/Annotations/AbstractIndex.php
@@ -25,6 +25,7 @@ abstract class AbstractIndex extends Annotation
 {
     public $keys = array();
     public $name;
+    /** @deprecated  */
     public $dropDups;
     public $background;
     public $safe;
diff --git a/lib/Doctrine/ODM/MongoDB/Mapping/ClassMetadata.php b/lib/Doctrine/ODM/MongoDB/Mapping/ClassMetadata.php
index 23589737f7..b1e7229f2d 100644
--- a/lib/Doctrine/ODM/MongoDB/Mapping/ClassMetadata.php
+++ b/lib/Doctrine/ODM/MongoDB/Mapping/ClassMetadata.php
@@ -889,6 +889,10 @@ public function setSlaveOkay($slaveOkay)
      */
     public function addIndex($keys, array $options = array())
     {
+        if (isset($options['dropDups'])) {
+            @trigger_error(sprintf('Ths "dropDups" option on indexes is deprecated and will be dropped in 2.0. Remove the "dropDups" options in class "%s".', $this->getName()), E_USER_DEPRECATED)
+        }
+
         $this->indexes[] = array(
             'keys' => array_map(function($value) {
                 if ($value == 1 || $value == -1) {