diff --git a/lib/jenkins_api_client/node.rb b/lib/jenkins_api_client/node.rb
index 4172ee0c..81ba2b35 100644
--- a/lib/jenkins_api_client/node.rb
+++ b/lib/jenkins_api_client/node.rb
@@ -128,8 +128,8 @@ def to_s
       #   )
       #
       def create_dumb_slave(params)
-        unless params[:name] && params[:slave_host] && params[:private_key_file]
-          raise ArgumentError, "Name, slave host, and private key file are" +
+        unless params[:name] && params[:slave_host] && ( params[:credentials_id] || params[:private_key_file] )
+          raise ArgumentError, "Name, slave host, and (private key file, or credentials) are" +
             " required for creating a slave."
         end