diff --git a/core/model/DataObject.php b/core/model/DataObject.php
index 7f803e88e..09f816ae4 100755
--- a/core/model/DataObject.php
+++ b/core/model/DataObject.php
@@ -2650,10 +2650,13 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 			$query->from[] = $join;
 			// In order to group by unique columns we have to group by everything listed in the select
 			foreach($query->select as $field) {
+				// Skip the _SortColumns; these are only going to be aggregate functions
+				if(preg_match('/AS\s+\"?_SortColumn/', $field, $matches)) {
+				
 				// Identify columns with aliases, and ignore the alias.  Making use of the alias in
 				// group by was causing problems when those queries were subsequently passed into
 				// SQLQuery::unlimitedRowCount.
-				if(preg_match('/^(.*)\s+AS\s+(\"[^"]+\")\s*$/', $field, $matches)) {
+				} else if(preg_match('/^(.*)\s+AS\s+(\"[^"]+\")\s*$/', $field, $matches)) {
 					$query->groupby[] = $matches[1];
 				// Otherwise just use the field as is
 				} else {
diff --git a/tests/DataObjectTest.php b/tests/DataObjectTest.php
index 022592990..650412865 100755
--- a/tests/DataObjectTest.php
+++ b/tests/DataObjectTest.php
@@ -738,6 +738,10 @@ class DataObjectTest extends SapphireTest {
 		$player = $newTeam->Players()->First();
 		$this->assertEquals('Sam', $player->FirstName);
 		$this->assertEquals("Prop", $player->Position);
+		
+		// Check that ordering a many-many relation by an aggregate column doesn't fail
+		$player = $this->objFromFixture('DataObjectTest_Player', 'player2');
+		$player->Teams("", "count(DISTINCT \"DataObjectTest_Team_Players\".\"DataObjectTest_PlayerID\") DESC");
 	}
 	
 	/**