diff --git a/ext/json/parser/parser.c b/ext/json/parser/parser.c
index b02aae8fb9..49048e1c47 100644
--- a/ext/json/parser/parser.c
+++ b/ext/json/parser/parser.c
@@ -1835,7 +1835,7 @@ static VALUE cParser_initialize(int argc, VALUE *argv, VALUE self)
     } else {
         json->max_nesting = 100;
         json->allow_nan = 0;
-        json->create_additions = 1;
+        json->create_additions = 0;
         json->create_id = rb_funcall(mJSON, i_create_id, 0);
         json->object_class = Qnil;
         json->array_class = Qnil;
diff --git a/ext/json/parser/parser.rl b/ext/json/parser/parser.rl
index d4e7a60e9d..fb0bb515de 100644
--- a/ext/json/parser/parser.rl
+++ b/ext/json/parser/parser.rl
@@ -730,7 +730,7 @@ static VALUE cParser_initialize(int argc, VALUE *argv, VALUE self)
     } else {
         json->max_nesting = 100;
         json->allow_nan = 0;
-        json->create_additions = 1;
+        json->create_additions = 0;
         json->create_id = rb_funcall(mJSON, i_create_id, 0);
         json->object_class = Qnil;
         json->array_class = Qnil;