Guard headers tool.
diff --git a/src/cpp/server/thread_pool.h b/src/cpp/server/thread_pool.h
index 9c1df0b..6157e40 100644
--- a/src/cpp/server/thread_pool.h
+++ b/src/cpp/server/thread_pool.h
@@ -31,8 +31,8 @@
*
*/
-#ifndef __GRPCPP_INTERNAL_SERVER_THREAD_POOL_H__
-#define __GRPCPP_INTERNAL_SERVER_THREAD_POOL_H__
+#ifndef GRPC_INTERNAL_CPP_SERVER_THREAD_POOL_H
+#define GRPC_INTERNAL_CPP_SERVER_THREAD_POOL_H
#include <grpc++/config.h>
#include <grpc++/thread_pool_interface.h>
@@ -62,4 +62,4 @@
} // namespace grpc
-#endif // __GRPCPP_INTERNAL_SERVER_THREAD_POOL_H__
+#endif // GRPC_INTERNAL_CPP_SERVER_THREAD_POOL_H