diff --git a/src/Type/Accessory/AccessoryDecimalIntegerStringType.php b/src/Type/Accessory/AccessoryDecimalIntegerStringType.php
index 7732aceffc..d965eb0ebc 100644
--- a/src/Type/Accessory/AccessoryDecimalIntegerStringType.php
+++ b/src/Type/Accessory/AccessoryDecimalIntegerStringType.php
@@ -456,6 +456,11 @@ public function getFiniteTypes(): array
 		return [];
 	}
 
+	public function getDefaultBaseType(): Type
+	{
+		return new StringType();
+	}
+
 	public function toPhpDocNode(): TypeNode
 	{
 		return new IdentifierTypeNode($this->inverse ? 'non-decimal-int-string' : 'decimal-int-string');