diff --git a/lib/rb/ext/constants.h b/lib/rb/ext/constants.h
index 76947e5..e7aec44 100644
--- a/lib/rb/ext/constants.h
+++ b/lib/rb/ext/constants.h
@@ -42,6 +42,7 @@
 extern ID write_i64_method_id;
 extern ID write_double_method_id;
 extern ID write_string_method_id;
+extern ID write_binary_method_id;
 extern ID write_map_begin_method_id;
 extern ID write_map_end_method_id;
 extern ID write_list_begin_method_id;
@@ -54,6 +55,7 @@
 extern ID read_i32_method_id;
 extern ID read_i64_method_id;
 extern ID read_string_method_id;
+extern ID read_binary_method_id;
 extern ID read_double_method_id;
 extern ID read_map_begin_method_id;
 extern ID read_map_end_method_id;
@@ -87,6 +89,7 @@
 extern VALUE value_sym;
 extern VALUE element_sym;
 extern VALUE class_sym;
+extern VALUE binary_sym;
 
 extern VALUE rb_cSet;
 extern VALUE thrift_module;