diff --git a/bin/cmdtest.rb b/bin/cmdtest.rb
index de30997..6ce37c5 100755
--- a/bin/cmdtest.rb
+++ b/bin/cmdtest.rb
@@ -183,7 +183,7 @@ module Cmdtest
     end
 
     def _path_separator
-      Config::CONFIG["PATH_SEPARATOR"] || ":"
+      RbConfig::CONFIG["PATH_SEPARATOR"] || ":"
     end
 
     def orig_env_path
diff --git a/lib/cmdtest/methodfilter.rb b/lib/cmdtest/methodfilter.rb
index 823ed30..67dd8b7 100644
--- a/lib/cmdtest/methodfilter.rb
+++ b/lib/cmdtest/methodfilter.rb
@@ -126,7 +126,7 @@ module Cmdtest
     end
 
     def _method_key(file, klass, method)
-      file + ":" + klass + "." + method
+      file + ":" + klass + "." + method.to_s
     end
 
   end