diff --git a/lib/msf/base/sessions/command_shell.rb b/lib/msf/base/sessions/command_shell.rb
index a5d094af3d..bfc76745c2 100644
--- a/lib/msf/base/sessions/command_shell.rb
+++ b/lib/msf/base/sessions/command_shell.rb
@@ -797,7 +797,7 @@ protected
   end
 
   def _file_transfer
-    raise NotImplementedError.new('Session does not support file transfers.') if @session_type.ends_with?(':winpty')
+    raise NotImplementedError.new('Session does not support file transfers.') if session_type.ends_with?(':winpty')
 
     FileTransfer.new(self)
   end