diff --git a/util/env_hdfs.cc b/util/env_hdfs.cc
index 30e796245..e7844e8dc 100644
--- a/util/env_hdfs.cc
+++ b/util/env_hdfs.cc
@@ -18,6 +18,7 @@
 #include <iostream>
 #include <sstream>
 #include "rocksdb/status.h"
+#include "util/string_util.h"
 
 #define HDFS_EXISTS 0
 #define HDFS_DOESNT_EXIST -1