diff --git a/lib/erl/include/thrift_protocol.hrl b/lib/erl/include/thrift_protocol.hrl
index f85f455..bc0acc8 100644
--- a/lib/erl/include/thrift_protocol.hrl
+++ b/lib/erl/include/thrift_protocol.hrl
@@ -20,12 +20,12 @@
 -ifndef(THRIFT_PROTOCOL_INCLUDED).
 -define(THRIFT_PROTOCOL_INCLUDED, true).
 
--record(protocol_message_begin, {name, type, seqid}).
--record(protocol_struct_begin, {name}).
--record(protocol_field_begin, {name, type, id}).
--record(protocol_map_begin, {ktype, vtype, size}).
--record(protocol_list_begin, {etype, size}).
--record(protocol_set_begin, {etype, size}).
+-record(protocol_message_begin, {name :: string(), type :: integer(), seqid :: integer()}).
+-record(protocol_struct_begin, {name :: string()}).
+-record(protocol_field_begin, {name :: string(), type :: integer(), id :: integer()}).
+-record(protocol_map_begin, {ktype :: integer(), vtype :: integer(), size :: integer()}).
+-record(protocol_list_begin, {etype :: integer(), size :: integer()}).
+-record(protocol_set_begin, {etype :: integer(), size :: integer()}).
 
 -type tprot_header_val() :: #protocol_message_begin{}
                           | #protocol_struct_begin{}