Addressing comments.
diff --git a/src/cpp/server/secure_server_credentials.h b/src/cpp/server/secure_server_credentials.h
index fa49d30..b9803f1 100644
--- a/src/cpp/server/secure_server_credentials.h
+++ b/src/cpp/server/secure_server_credentials.h
@@ -31,6 +31,9 @@
*
*/
+#ifndef GRPC_INTERNAL_CPP_SERVER_SECURE_SERVER_CREDENTIALS_H
+#define GRPC_INTERNAL_CPP_SERVER_SECURE_SERVER_CREDENTIALS_H
+
#include <grpc/grpc_security.h>
#include <grpc++/server_credentials.h>
@@ -54,3 +57,4 @@
} // namespace grpc
+#endif // GRPC_INTERNAL_CPP_SERVER_SECURE_SERVER_CREDENTIALS_H