diff --git a/include/ndn-cpp/security/certificate/public-key.hpp b/include/ndn-cpp/security/certificate/public-key.hpp
index fa8724f..0a48b5f 100644
--- a/include/ndn-cpp/security/certificate/public-key.hpp
+++ b/include/ndn-cpp/security/certificate/public-key.hpp
@@ -7,7 +7,7 @@
  */
 
 #ifndef NDN_PUBLIC_KEY_HPP
-#define	NDN_PUBLIC_KEY_HPP
+#define NDN_PUBLIC_KEY_HPP
 
 #include "../../util/blob.hpp"
 #include "../../encoding/oid.hpp"