diff --git a/src/Illuminate/Database/Eloquent/Relations/BelongsToMany.php b/src/Illuminate/Database/Eloquent/Relations/BelongsToMany.php
index 1147c2a45368..5791d2bb4d81 100755
--- a/src/Illuminate/Database/Eloquent/Relations/BelongsToMany.php
+++ b/src/Illuminate/Database/Eloquent/Relations/BelongsToMany.php
@@ -7,6 +7,7 @@
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\Collection;
+use Illuminate\Support\Collection as BaseCollection;
 use Illuminate\Database\Eloquent\ModelNotFoundException;
 
 class BelongsToMany extends Relation
@@ -872,7 +873,7 @@ public function syncWithoutDetaching($ids)
     /**
      * Sync the intermediate tables with a list of IDs or collection of models.
      *
-     * @param  \Illuminate\Database\Eloquent\Collection|array  $ids
+     * @param  \Illuminate\Database\Eloquent\Collection|\Illuminate\Support\Collection|array  $ids
      * @param  bool   $detaching
      * @return array
      */
@@ -886,6 +887,10 @@ public function sync($ids, $detaching = true)
             $ids = $ids->modelKeys();
         }
 
+        if ($ids instanceof BaseCollection) {
+            $ids = $ids->toArray();
+        }
+
         // First we need to attach any of the associated models that are not currently
         // in this joining table. We'll spin through the given IDs, checking to see
         // if they exist in the array of current ones, and if not we will insert.
diff --git a/tests/Database/DatabaseEloquentBelongsToManyTest.php b/tests/Database/DatabaseEloquentBelongsToManyTest.php
index b908ee26b4e5..25264b45ab34 100755
--- a/tests/Database/DatabaseEloquentBelongsToManyTest.php
+++ b/tests/Database/DatabaseEloquentBelongsToManyTest.php
@@ -628,7 +628,7 @@ public function testTouchIfTouching()
         $relation->touchIfTouching();
     }
 
-    public function testSyncMethodConvertsCollectionToArrayOfKeys()
+    public function testSyncMethodConvertsEloquentCollectionToArrayOfKeys()
     {
         $relation = $this->getMockBuilder('Illuminate\Database\Eloquent\Relations\BelongsToMany')->setMethods(['attach', 'detach', 'touchIfTouching', 'formatRecordsList'])->setConstructorArgs($this->getRelationArguments())->getMock();
         $query = m::mock('stdClass');
@@ -647,6 +647,21 @@ public function testSyncMethodConvertsCollectionToArrayOfKeys()
         $relation->sync($collection);
     }
 
+    public function testSyncMethodConvertsBaseCollectionToArrayOfKeys()
+    {
+        $relation = $this->getMockBuilder('Illuminate\Database\Eloquent\Relations\BelongsToMany')->setMethods(['attach', 'detach', 'touchIfTouching', 'formatRecordsList'])->setConstructorArgs($this->getRelationArguments())->getMock();
+        $query = m::mock('stdClass');
+        $query->shouldReceive('from')->once()->with('user_role')->andReturn($query);
+        $query->shouldReceive('where')->once()->with('user_id', 1)->andReturn($query);
+        $relation->getQuery()->shouldReceive('getQuery')->andReturn($mockQueryBuilder = m::mock('StdClass'));
+        $mockQueryBuilder->shouldReceive('newQuery')->once()->andReturn($query);
+        $query->shouldReceive('pluck')->once()->with('role_id')->andReturn(new BaseCollection([1, 2, 3]));
+
+        $collection = new BaseCollection([1, 2, 3]);
+        $relation->expects($this->once())->method('formatRecordsList')->with([1, 2, 3])->will($this->returnValue([1 => [], 2 => [], 3 => []]));
+        $relation->sync($collection);
+    }
+
     public function testWherePivotParamsUsedForNewQueries()
     {
         $relation = $this->getMockBuilder('Illuminate\Database\Eloquent\Relations\BelongsToMany')->setMethods(['attach', 'detach', 'touchIfTouching', 'formatRecordsList'])->setConstructorArgs($this->getRelationArguments())->getMock();