diff --git a/ext/nokogiri/xml_reader.c b/ext/nokogiri/xml_reader.c
index 93d9fa7324..0895ea6a72 100644
--- a/ext/nokogiri/xml_reader.c
+++ b/ext/nokogiri/xml_reader.c
@@ -723,8 +723,6 @@ rb_xml_reader_encoding(VALUE rb_reader)
   constructor_encoding = rb_iv_get(rb_reader, "@encoding");
   if (RTEST(constructor_encoding)) {
     return constructor_encoding;
-  } else {
-      rb_iv_set(self, "@encoding", NOKOGIRI_STR_NEW2("UTF-8"));
   }
 
   Data_Get_Struct(rb_reader, xmlTextReader, c_reader);