diff --git a/apps/openmw/mwmechanics/obstacle.hpp b/apps/openmw/mwmechanics/obstacle.hpp
index 920e2e794..12030b2be 100644
--- a/apps/openmw/mwmechanics/obstacle.hpp
+++ b/apps/openmw/mwmechanics/obstacle.hpp
@@ -1,4 +1,5 @@
 #ifndef OPENMW_MECHANICS_OBSTACLE_H
+#define OPENMW_MECHANICS_OBSTACLE_H
 
 namespace MWWorld
 {