diff --git a/packages/@aws-cdk/aws-ssm/lib/parameter.ts b/packages/@aws-cdk/aws-ssm/lib/parameter.ts
index 99afccb82fda3..a0b21319597e0 100644
--- a/packages/@aws-cdk/aws-ssm/lib/parameter.ts
+++ b/packages/@aws-cdk/aws-ssm/lib/parameter.ts
@@ -141,7 +141,7 @@ export interface StringParameterProps extends ParameterOptions {
   /**
    * The data type of the parameter, such as `text` or `aws:ec2:image`.
    *
-   * @default - undefined
+   * @default ParameterDataType.TEXT
    */
   readonly dataType?: ParameterDataType;
 }