diff --git a/pkg/models/task_collection.go b/pkg/models/task_collection.go
index f6a22a121a4..c2936ff7086 100644
--- a/pkg/models/task_collection.go
+++ b/pkg/models/task_collection.go
@@ -74,7 +74,8 @@ func validateTaskField(fieldName string) error {
 		taskPropertyUpdated,
 		taskPropertyPosition,
 		taskPropertyKanbanPosition,
-		taskPropertyBucketID:
+		taskPropertyBucketID,
+		taskPropertyIndex:
 		return nil
 	}
 	return ErrInvalidTaskField{TaskField: fieldName}
diff --git a/pkg/models/task_collection_sort.go b/pkg/models/task_collection_sort.go
index 7b72cc2090b..4badd799b79 100644
--- a/pkg/models/task_collection_sort.go
+++ b/pkg/models/task_collection_sort.go
@@ -46,6 +46,7 @@ const (
 	taskPropertyPosition       string = "position"
 	taskPropertyKanbanPosition string = "kanban_position"
 	taskPropertyBucketID       string = "bucket_id"
+	taskPropertyIndex          string = "index"
 )
 
 const (
diff --git a/pkg/models/tasks.go b/pkg/models/tasks.go
index 707e065909c..e86e7d6acf7 100644
--- a/pkg/models/tasks.go
+++ b/pkg/models/tasks.go
@@ -309,10 +309,10 @@ func getRawTasksForLists(s *xorm.Session, lists []*List, a web.Auth, opts *taskO
 		// Because it does not have support for NULLS FIRST or NULLS LAST we work around this by
 		// first sorting for null (or not null) values and then the order we actually want to.
 		if db.Type() == schemas.MYSQL {
-			orderby += param.sortBy + " IS NULL, "
+			orderby += "`" + param.sortBy + "` IS NULL, "
 		}
 
-		orderby += param.sortBy + " " + param.orderBy.String()
+		orderby += "`" + param.sortBy + "` " + param.orderBy.String()
 
 		// Postgres and sqlite allow us to control how columns with null values are sorted.
 		// To make that consistent with the sort order we have and other dbms, we're adding a separate clause here.