diff --git a/tests/DataHelpers.cpp b/tests/DataHelpers.cpp
index 1f0bd949..a5cb7df0 100644
--- a/tests/DataHelpers.cpp
+++ b/tests/DataHelpers.cpp
@@ -10,6 +10,7 @@
 #include <iostream>
 #include <sstream>
 #include <cstring>
+#include <fstream>
 
 void load_txt(DataPoints& dp, std::istream& in)
 {