diff --git a/model/SQLQuery.php b/model/SQLQuery.php
index 44c4f5d0a..6e49d9b7f 100644
--- a/model/SQLQuery.php
+++ b/model/SQLQuery.php
@@ -1066,10 +1066,20 @@ class SQLQuery {
 	 * @param $alias An optional alias for the aggregate column.
 	 */
 	public function aggregate($column, $alias = null) {
-		
 		$clone = clone $this;
-		$clone->setLimit($this->limit);
-		$clone->setOrderBy($this->orderby);
+
+		// don't set an ORDER BY clause if no limit has been set. It doesn't make
+		// sense to add an ORDER BY if there is no limit, and it will break
+		// queries to databases like MSSQL if you do so. Note that the reason
+		// this came up is because DataQuery::initialiseQuery() introduces
+		// a default sort.
+		if($this->limit) {
+			$clone->setLimit($this->limit);
+			$clone->setOrderBy($this->orderby);
+		} else {
+			$clone->setOrderBy(array());
+		}
+
 		$clone->setGroupBy($this->groupby);
 		if($alias) {
 			$clone->setSelect(array());
@@ -1077,7 +1087,6 @@ class SQLQuery {
 		} else {
 			$clone->setSelect($column);
 		}
-		
 
 		return $clone;
 	}
diff --git a/tests/model/SQLQueryTest.php b/tests/model/SQLQueryTest.php
index 956fa244c..d6cfe174a 100755
--- a/tests/model/SQLQueryTest.php
+++ b/tests/model/SQLQueryTest.php
@@ -414,6 +414,31 @@ class SQLQueryTest extends SapphireTest {
 		$this->assertEquals(array(2), $result->column('cnt'));
 	}
 
+	/**
+	 * Tests that an ORDER BY is only added if a LIMIT is set.
+	 */
+	public function testAggregateNoOrderByIfNoLimit() {
+		$query = new SQLQuery();
+		$query->setFrom('"SQLQueryTest_DO"');
+		$query->setOrderBy('Common');
+		$query->setLimit(array());
+
+		$aggregate = $query->aggregate('MAX("ID")');
+		$limit = $aggregate->getLimit();
+		$this->assertEquals(array(), $aggregate->getOrderBy());
+		$this->assertEquals(array(), $limit);
+
+		$query = new SQLQuery();
+		$query->setFrom('"SQLQueryTest_DO"');
+		$query->setOrderBy('Common');
+		$query->setLimit(2);
+
+		$aggregate = $query->aggregate('MAX("ID")');
+		$limit = $aggregate->getLimit();
+		$this->assertEquals(array('Common' => 'ASC'), $aggregate->getOrderBy());
+		$this->assertEquals(array('start' => 0, 'limit' => 2), $limit);
+	}
+
 	/**
 	 * Test that "_SortColumn0" is added for an aggregate in the ORDER BY
 	 * clause, in combination with a LIMIT and GROUP BY clause.