diff --git a/include/xgboost/c_api.h b/include/xgboost/c_api.h
index c1cf90345198..740e2ed95644 100644
--- a/include/xgboost/c_api.h
+++ b/include/xgboost/c_api.h
@@ -1,5 +1,5 @@
 /*!
- * Copyright (c) 2015 by Contributors
+ * Copyright (c) 2015-2019 by Contributors
  * \file c_api.h
  * \author Tianqi Chen
  * \brief C API of XGBoost, used for interfacing to other languages.
diff --git a/src/c_api/c_api.cc b/src/c_api/c_api.cc
index c2484437b85a..62b64d09222a 100644
--- a/src/c_api/c_api.cc
+++ b/src/c_api/c_api.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2014 by Contributors
+// Copyright (c) 2014-2019 by Contributors
 
 #include <xgboost/data.h>
 #include <xgboost/learner.h>
diff --git a/src/data/data.cc b/src/data/data.cc
index 437e4ea5e60d..9cb6eff0f9c2 100644
--- a/src/data/data.cc
+++ b/src/data/data.cc
@@ -1,5 +1,5 @@
 /*!
- * Copyright 2015 by Contributors
+ * Copyright 2015-2019 by Contributors
  * \file data.cc
  */
 #include <xgboost/data.h>