diff --git a/bootstraptest/runner.rb b/bootstraptest/runner.rb
index c8ba8244076986..aa6b24a2ba1489 100755
--- a/bootstraptest/runner.rb
+++ b/bootstraptest/runner.rb
@@ -549,7 +549,7 @@ def get_result_string(opt = '', **argh)
   end
 
   def make_srcfile(frozen_string_literal: nil)
-    filename = "bootstraptest.#{self.path}_#{self.lineno}_#{self.id}.rb"
+    filename = File.join(Dir.pwd, "btest.#{self.path}_L#{self.lineno}_N#{self.id}.rb")
     File.open(filename, 'w') {|f|
       f.puts "#frozen_string_literal:true" if frozen_string_literal
       f.puts "GC.stress = true" if $stress