diff --git a/lib/rb/ext/constants.h b/lib/rb/ext/constants.h
index 9ea00d2..3bfac88 100644
--- a/lib/rb/ext/constants.h
+++ b/lib/rb/ext/constants.h
@@ -76,6 +76,9 @@
 extern ID read_all_method_id;
 extern ID read_into_buffer_method_id;
 extern ID native_qmark_method_id;
+extern ID force_binary_encoding_id;
+extern ID convert_to_utf8_byte_buffer_id;
+extern ID convert_to_string_id;
 
 extern ID fields_const_id;
 extern ID transport_ivar_id;
@@ -92,5 +95,6 @@
 extern VALUE rb_cSet;
 extern VALUE thrift_module;
 extern VALUE thrift_types_module;
+extern VALUE thrift_bytes_module;
 extern VALUE class_thrift_protocol;
 extern VALUE protocol_exception_class;