diff --git a/SfMToyLib/SfM.cpp b/SfMToyLib/SfM.cpp
index 464dcf8..6a5b261 100644
--- a/SfMToyLib/SfM.cpp
+++ b/SfMToyLib/SfM.cpp
@@ -33,6 +33,7 @@
 #include <algorithm>
 #include <thread>
 #include <mutex>
+#include <fstream>
 
 #include <opencv2/highgui/highgui.hpp>
 #include <opencv2/calib3d/calib3d.hpp>