Guard headers tool.
diff --git a/src/cpp/client/channel.h b/src/cpp/client/channel.h
index e3edcf7..63c6e2b 100644
--- a/src/cpp/client/channel.h
+++ b/src/cpp/client/channel.h
@@ -31,8 +31,8 @@
*
*/
-#ifndef __GRPCPP_INTERNAL_CLIENT_CHANNEL_H__
-#define __GRPCPP_INTERNAL_CLIENT_CHANNEL_H__
+#ifndef GRPC_INTERNAL_CPP_CLIENT_CHANNEL_H
+#define GRPC_INTERNAL_CPP_CLIENT_CHANNEL_H
#include <memory>
@@ -68,4 +68,4 @@
} // namespace grpc
-#endif // __GRPCPP_INTERNAL_CLIENT_CHANNEL_H__
+#endif // GRPC_INTERNAL_CPP_CLIENT_CHANNEL_H