diff --git a/packages/compiler-cli/ngcc/src/main.ts b/packages/compiler-cli/ngcc/src/main.ts
index c69424fa91..0fc5f7b96d 100644
--- a/packages/compiler-cli/ngcc/src/main.ts
+++ b/packages/compiler-cli/ngcc/src/main.ts
@@ -31,7 +31,8 @@ export interface NgccOptions {
   /** The absolute path to the `node_modules` folder that contains the packages to process. */
   basePath: string;
   /**
-   * The path, relative to `basePath` to the primary package to be processed.
+   * The path to the primary package to be processed. If not absolute then it must be relative to
+   * `basePath`.
    *
    * All its dependencies will need to be processed too.
    */