1 files changed, 2 insertions, 0 deletions
diff --git a/gc.h b/gc.h
index 2ba46c9250..4ddff2ddf3 100644
--- a/gc.h
+++ b/gc.h
@@ -83,6 +83,8 @@ int ruby_get_stack_grow_direction(volatile VALUE *addr);
 #endif
 #define IS_STACK_DIR_UPPER() STACK_DIR_UPPER(1,0)
 
+const char *rb_obj_info(VALUE obj);
+
 RUBY_SYMBOL_EXPORT_BEGIN
 
 /* exports for objspace module */