diff --git a/packages/@aws-cdk/aws-lambda/lib/runtime.ts b/packages/@aws-cdk/aws-lambda/lib/runtime.ts
index 0fd19c7b05396..891c02c9c21b6 100644
--- a/packages/@aws-cdk/aws-lambda/lib/runtime.ts
+++ b/packages/@aws-cdk/aws-lambda/lib/runtime.ts
@@ -161,24 +161,25 @@ export class Runtime {
 
   /**
    * The .NET Core 1.0 runtime (dotnetcore1.0)
-   * Legacy runtime no longer supported by AWS Lambda. Migrate to the latest .NET Core runtime.
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest .NET Core runtime.
    */
   public static readonly DOTNET_CORE_1 = new Runtime('dotnetcore1.0', RuntimeFamily.DOTNET_CORE);
 
   /**
    * The .NET Core 2.0 runtime (dotnetcore2.0)
-   * Legacy runtime no longer supported by AWS Lambda. Migrate to the latest .NET Core runtime.
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest .NET Core runtime.
    */
   public static readonly DOTNET_CORE_2 = new Runtime('dotnetcore2.0', RuntimeFamily.DOTNET_CORE);
 
   /**
    * The .NET Core 2.1 runtime (dotnetcore2.1)
-   * Legacy runtime no longer supported by AWS Lambda. Migrate to the latest .NET Core runtime.
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest .NET Core runtime.
    */
   public static readonly DOTNET_CORE_2_1 = new Runtime('dotnetcore2.1', RuntimeFamily.DOTNET_CORE);
 
   /**
    * The .NET Core 3.1 runtime (dotnetcore3.1)
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest .NET Core runtime.
    */
   public static readonly DOTNET_CORE_3_1 = new Runtime('dotnetcore3.1', RuntimeFamily.DOTNET_CORE);
 
@@ -189,7 +190,7 @@ export class Runtime {
 
   /**
    * The Ruby 2.5 runtime (ruby2.5)
-   * Legacy runtime no longer supported by AWS Lambda. Migrate to the latest Ruby runtime.
+   * @deprecated Legacy runtime no longer supported by AWS Lambda. Migrate to the latest Ruby runtime.
    */
   public static readonly RUBY_2_5 = new Runtime('ruby2.5', RuntimeFamily.RUBY);