diff --git a/src/one-body-sample.cc b/src/one-body-sample.cc
index c049dcef0f7de95d4688396ed880d25dabdd6d84..22f432e9841b0742908e53f48d78bfa7788c933a 100644
--- a/src/one-body-sample.cc
+++ b/src/one-body-sample.cc
@@ -26,6 +26,7 @@
 
 #include <cmath>
 #include <exception>
+#include <fstream>
 #include <iostream>
 
 #include <boost/format.hpp>