diff --git a/src/utils/endian.cpp b/src/utils/endian.cpp
index 589089b6..56f6645d 100644
--- a/src/utils/endian.cpp
+++ b/src/utils/endian.cpp
@@ -22,6 +22,7 @@
 /// \brief contains file I/O functions that write/read data LSB first.
 
 #include <stdio.h>
+#include <ostream>
 #include "../types.h"
 #include "endian.h"