diff --git a/test/support/test_case.rb b/test/support/test_case.rb
index ad190534..4488a456 100644
--- a/test/support/test_case.rb
+++ b/test/support/test_case.rb
@@ -14,7 +14,7 @@ def knife_command(cmd_class, *args)
     command.ui.stubs(:msg)
     command.ui.stubs(:warn)
     Chef::Config[:verbosity] = 0
-    command.config[:config_file] = "#{__dir__}/knife.rb"
+    command.config[:config_file] = "#{File.dirname(__FILE__)}/knife.rb"
     command.configure_chef
     command
   end