diff --git a/lib/yard/parser/ruby/legacy/ruby_lex.rb b/lib/yard/parser/ruby/legacy/ruby_lex.rb
index 40f805ff0..2f139d0d5 100644
--- a/lib/yard/parser/ruby/legacy/ruby_lex.rb
+++ b/lib/yard/parser/ruby/legacy/ruby_lex.rb
@@ -978,7 +978,7 @@ def identify_gvar
       end
 
       def identify_identifier
-        token = ""
+        token = String.new(encoding: Encoding::UTF_8)
         token.concat getc if peek(0) =~ /[$@]/
         token.concat getc if peek(0) == "@"