diff --git a/ndn-cpp/closure.hpp b/ndn-cpp/closure.hpp
index 9055157..e8cc191 100644
--- a/ndn-cpp/closure.hpp
+++ b/ndn-cpp/closure.hpp
@@ -8,7 +8,7 @@
  */
 
 #ifndef NDN_CLOSURE_HPP
-#define	NDN_CLOSURE_HPP
+#define NDN_CLOSURE_HPP
 
 #include "common.hpp"