diff --git a/src/class/OptionRegistry.js b/src/class/OptionRegistry.js
index 830e9584c78e04e1a6f4a15dc838a002cbe85ca9..894bd08c2fac7441e2c21bfe5383380509d56717 100644
--- a/src/class/OptionRegistry.js
+++ b/src/class/OptionRegistry.js
@@ -18,7 +18,7 @@ defaults.useDefaultValue = false;
 defaults.requiredOnly = false;
 
 defaults.minItems = 0;
-defaults.maxItems = null;
+defaults.maxItems = 1;
 defaults.minLength = 0;
 defaults.maxLength = null;