Code style: Replace tab with space.
diff --git a/include/ndn-cpp/c/forwarding-flags.h b/include/ndn-cpp/c/forwarding-flags.h
index ba6f6b5..863bf04 100644
--- a/include/ndn-cpp/c/forwarding-flags.h
+++ b/include/ndn-cpp/c/forwarding-flags.h
@@ -5,9 +5,9 @@
  */
 
 #ifndef NDN_FORWARDING_FLAGS_H
-#define	NDN_FORWARDING_FLAGS_H
+#define NDN_FORWARDING_FLAGS_H
 
-#ifdef	__cplusplus
+#ifdef __cplusplus
 extern "C" {
 #endif
 
@@ -48,7 +48,7 @@
 void ndn_ForwardingFlags_setForwardingEntryFlags(struct ndn_ForwardingFlags *self, int forwardingEntryFlags);
 
 
-#ifdef	__cplusplus
+#ifdef __cplusplus
 }
 #endif