diff --git a/src/mlpack/core/tree/rectangle_tree/x_tree_split.hpp b/src/mlpack/core/tree/rectangle_tree/x_tree_split.hpp
index cab64c743f..fb8b76f01f 100644
--- a/src/mlpack/core/tree/rectangle_tree/x_tree_split.hpp
+++ b/src/mlpack/core/tree/rectangle_tree/x_tree_split.hpp
@@ -29,8 +29,8 @@ const double MAX_OVERLAP = 0.2;
  * as necessary.
  */
 template<typename DescentType,
-	 typename StatisticType,
-	 typename MatType>
+         typename StatisticType,
+         typename MatType>
 class XTreeSplit
 {
 public: