diff --git a/cpp/testNonlinearFactor.cpp b/cpp/testNonlinearFactor.cpp
index 93ccbac4f..837fd719a 100644
--- a/cpp/testNonlinearFactor.cpp
+++ b/cpp/testNonlinearFactor.cpp
@@ -13,7 +13,7 @@
 
 #include "Matrix.h"
 #include "smallExample.h"
-#include "Simulated2D.h"
+#include "simulated2D.h"
 #include "GaussianFactor.h"
 
 using namespace std;