diff --git a/test/ruby/test_parse.rb b/test/ruby/test_parse.rb
index 65b8f87ad0..625b6eb223 100644
--- a/test/ruby/test_parse.rb
+++ b/test/ruby/test_parse.rb
@@ -1090,7 +1090,7 @@ x = __ENCODING__
 
       v2 = <<~HEREDOC
         something
-        #{other = "/#{var}"}
+        #{_other = "/#{var}"}
       HEREDOC
 
       v3 = <<~HEREDOC