diff --git a/src/cache_node.cpp b/src/cache_node.cpp
index 8cf8cb4..f1410ad 100644
--- a/src/cache_node.cpp
+++ b/src/cache_node.cpp
@@ -19,6 +19,7 @@
  */
 
 #include <iomanip>
+#include <sstream>
 
 #include "s3fs.h"
 #include "s3fs_logger.h"
diff --git a/src/cache_node.h b/src/cache_node.h
index b1d0d0c..a2bd9be 100644
--- a/src/cache_node.h
+++ b/src/cache_node.h
@@ -21,8 +21,8 @@
 #ifndef S3FS_CACHE_NODE_H_
 #define S3FS_CACHE_NODE_H_
 
+#include <iosfwd>
 #include <memory>
-#include <sstream>
 #include <mutex>
 
 #include "common.h"