diff --git a/plugins/synced_folders/smb/errors.rb b/plugins/synced_folders/smb/errors.rb
index f73d04bfa..4a5d2503e 100644
--- a/plugins/synced_folders/smb/errors.rb
+++ b/plugins/synced_folders/smb/errors.rb
@@ -19,7 +19,7 @@ module VagrantPlugins
       end
 
       class PowershellVersion < SMBError
-        error_Key(:powershell_version)
+        error_key(:powershell_version)
       end
 
       class WindowsHostRequired < SMBError