diff --git a/packages/aws-cdk-lib/aws-lambda/lib/runtime.ts b/packages/aws-cdk-lib/aws-lambda/lib/runtime.ts
index 5abc99474a5e4..2f67978cc1420 100644
--- a/packages/aws-cdk-lib/aws-lambda/lib/runtime.ts
+++ b/packages/aws-cdk-lib/aws-lambda/lib/runtime.ts
@@ -228,6 +228,7 @@ export class Runtime {
 
   /**
    * The Go 1.x runtime (go1.x)
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the PROVIDED_AL2 runtime.
    */
   public static readonly GO_1_X = new Runtime('go1.x', RuntimeFamily.GO);