diff --git a/src/treelearner/linear_tree_learner.h b/src/treelearner/linear_tree_learner.h
index 376040cc6583..ff29760e1693 100644
--- a/src/treelearner/linear_tree_learner.h
+++ b/src/treelearner/linear_tree_learner.h
@@ -5,6 +5,7 @@
 #ifndef LIGHTGBM_TREELEARNER_LINEAR_TREE_LEARNER_H_
 #define LIGHTGBM_TREELEARNER_LINEAR_TREE_LEARNER_H_
 
+#include <string>
 #include <cmath>
 #include <cstdio>
 #include <memory>