diff --git a/include/msckf_vio/feature.hpp b/include/msckf_vio/feature.hpp
index c5d02ff..5f6b23e 100644
--- a/include/msckf_vio/feature.hpp
+++ b/include/msckf_vio/feature.hpp
@@ -6,7 +6,7 @@
  */
 
 #ifndef MSCKF_VIO_FEATURE_H
-#define MSCKF_VIO_FEATURE_H
+#define MSCKF_VIO_FEATURE_Hs
 
 #include <iostream>
 #include <map>