diff --git a/packages/@aws-cdk/core/lib/custom-resource-provider/custom-resource-provider.ts b/packages/@aws-cdk/core/lib/custom-resource-provider/custom-resource-provider.ts
index 8550efd7c72bd..d6b0a2db982c7 100644
--- a/packages/@aws-cdk/core/lib/custom-resource-provider/custom-resource-provider.ts
+++ b/packages/@aws-cdk/core/lib/custom-resource-provider/custom-resource-provider.ts
@@ -85,7 +85,7 @@ export enum CustomResourceProviderRuntime {
   /**
    * Node.js 12.x
    */
-  NODEJS_12 = 'nodejs12'
+  NODEJS_12 = 'nodejs12.x'
 }
 
 /**
@@ -210,7 +210,7 @@ export class CustomResourceProvider extends CoreConstruct {
         MemorySize: memory.toMebibytes(),
         Handler: `${ENTRYPOINT_FILENAME}.handler`,
         Role: role.getAtt('Arn'),
-        Runtime: 'nodejs12.x',
+        Runtime: props.runtime,
         Environment: this.renderEnvironmentVariables(props.environment),
         Description: props.description ?? undefined,
       },