diff --git a/src/data/sparse_page_dmatrix.h b/src/data/sparse_page_dmatrix.h
index 02a48bb5c..4bd750a20 100644
--- a/src/data/sparse_page_dmatrix.h
+++ b/src/data/sparse_page_dmatrix.h
@@ -1,7 +1,7 @@
 /*!
  * Copyright 2015 by Contributors
- * \file simple_dmatrix.h
- * \brief In-memory version of DMatrix.
+ * \file sparse_page_dmatrix.h
+ * \brief External-memory version of DMatrix.
  * \author Tianqi Chen
  */
 #ifndef XGBOOST_DATA_SPARSE_PAGE_DMATRIX_H_