diff --git a/README.md b/README.md
index 66ab25f..a5389d3 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,4 @@
+
 # FullTextSearch module
 
 [![Build Status](https://secure.travis-ci.org/silverstripe/silverstripe-fulltextsearch.png?branch=master)](http://travis-ci.org/silverstripe/silverstripe-fulltextsearch)
diff --git a/code/search/SearchVariantSubsites.php b/code/search/SearchVariantSubsites.php
index 8f52ac2..63ad366 100644
--- a/code/search/SearchVariantSubsites.php
+++ b/code/search/SearchVariantSubsites.php
@@ -60,9 +60,21 @@ class SearchVariantSubsites extends SearchVariant
         ));
     }
 
-
+    /**
+     * This field has been altered to allow a user to obtain search results for a particular subsite
+     * When attempting to do this in project code, SearchVariantSubsites kicks and overwrites any filter you've applied
+     * This fix prevents the module from doing this if a filter is applied on the index or the query, or if a field is
+     * being excluded specifically before being executed.
+     *
+     * A pull request has been raised for this issue. Once accepted this forked module can be deleted and the parent
+     * project should be used instead.
+     */
     public function alterQuery($query, $index)
     {
+        if ($this->isFieldFiltered('_subsite', $query)) {
+            return;
+        }
+
         $subsite = Subsite::currentSubsiteID();
         $query->filter('_subsite', array($subsite, SearchQuery::$missing));
     }
@@ -109,4 +121,19 @@ class SearchVariantSubsites extends SearchVariant
             $writes[$key]['statefulids'] = $next;
         }
     }
+
+    /**
+     * Determine if a field with a certain name is filtered by the search query or on the index
+     * This is the equivalent of saying "show me the results that do ONLY contain this value"
+     * @param $field string name of the field being filtered
+     * @param $query SearchQuery currently being executed
+     * @param $index SearchIndex which specifies a filter field
+     * @return bool true if $field is being filtered, false if it is not being filtered
+     */
+    protected function isFieldFiltered($field, $query)
+    {
+        $queryHasFilter = !empty($query->require[$field]);
+
+        return $queryHasFilter;
+    }
 }
diff --git a/tests/SearchVariantSubsitesTest.php b/tests/SearchVariantSubsitesTest.php
new file mode 100644
index 0000000..eb29375
--- /dev/null
+++ b/tests/SearchVariantSubsitesTest.php
@@ -0,0 +1,91 @@
+<?php
+
+class SearchVariantSubsiteTest extends SapphireTest
+{
+
+    private static $index = null;
+
+
+    public function setUp()
+    {
+        parent::setUp();
+
+        // Check versioned available
+        if (!class_exists('Subsite')) {
+            return $this->markTestSkipped('The subsites module is not installed');
+        }
+
+        if (self::$index === null) {
+            self::$index = singleton('SearchVariantSubsiteTest');
+        }
+
+        SearchUpdater::bind_manipulation_capture();
+
+        Config::inst()->update('Injector', 'SearchUpdateProcessor', array(
+            'class' => 'SearchUpdateImmediateProcessor'
+        ));
+
+        FullTextSearch::force_index_list(self::$index);
+        SearchUpdater::clear_dirty_indexes();
+    }
+
+    public function testQueryIsAlteredWhenSubsiteNotSet()
+    {
+        $index = new SolrIndexTest_FakeIndex();
+        $query = new SearchQuery();
+
+        //typical behaviour: nobody is explicitly filtering on subsite, so the search variant adds a filter to the query
+        $this->assertArrayNotHasKey('_subsite', $query->require);
+        $variant = new SearchVariantSubsites();
+        $variant->alterDefinition('SearchUpdaterTest_Container', $index);
+        $variant->alterQuery($query, $index);
+
+        //check that the "default" query has been put in place: it's not empty, and we're searching on Subsite ID:0 and
+        // an object of SearchQuery::missing
+        $this->assertNotEmpty($query->require['_subsite']);
+        $this->assertEquals(0, $query->require['_subsite'][0]);
+
+        //check that SearchQuery::missing is set (by default, it is an object of stdClass)
+        $this->assertInstanceOf('stdClass', $query->require['_subsite'][1]);
+    }
+
+
+    public function testQueryIsAlteredWhenSubsiteIsSet()
+    {
+        //now we want to test if somebody has already applied the _subsite filter to the query
+        $index = new SolrIndexTest_FakeIndex();
+        $query = new SearchQuery();
+
+        //check that _subsite is not applied yet
+        //this key should not be exist until the SearchVariant applies it later
+        $this->assertArrayNotHasKey('_subsite', $query->require);
+
+        //apply the subsite filter on the query (for example, if it's passed into a controller and set before searching)
+        //we've chosen an arbirary value of 2 here, to check if it is changed later
+        $query->filter('_subsite', 2);
+        $this->assertNotEmpty($query->require['_subsite']);
+
+        //apply the search variant's definition and query
+        $variant = new SearchVariantSubsites();
+        $variant->alterDefinition('SearchUpdaterTest_Container', $index);
+
+        //the protected function isFieldFiltered is implicitly tested here
+        $variant->alterQuery($query, $index);
+
+        //confirm that the query has been altered, but NOT with default values
+        //first check that _subsite filter is not empty
+        $this->assertNotEmpty($query->require['_subsite']);
+        //subsite filter first value is not 0
+        $this->assertNotEquals(0, $query->require['_subsite'][0]);
+
+        //subsite filter SearchQuery::missing should not be set so its expected location is empty
+        $this->assertArrayNotHasKey(1, $query->require['_subsite']);
+
+        //subsite filter has been modified with our arbitrary test value. The second value is not set
+        //this proves that the query has not been altered by the variant
+        $this->assertEquals(2, $query->require['_subsite'][0]);
+
+    }
+
+}
+