diff --git a/ndn-cpp/key.hpp b/ndn-cpp/key.hpp
index d137b60..a715bf3 100644
--- a/ndn-cpp/key.hpp
+++ b/ndn-cpp/key.hpp
@@ -4,7 +4,7 @@
  */
 
 #ifndef NDN_KEY_HPP
-#define	NDN_KEY_HPP
+#define NDN_KEY_HPP
 
 #include <vector>
 #include "c/key.h"