diff --git a/src/declarations/stencil-public-compiler.ts b/src/declarations/stencil-public-compiler.ts
index b45c7708076d..28c4831b41de 100644
--- a/src/declarations/stencil-public-compiler.ts
+++ b/src/declarations/stencil-public-compiler.ts
@@ -319,6 +319,9 @@ export interface ConfigExtras {
    * if it's determined that shadow dom is already natively supported by the browser then
    * it does not request the shim. When set to `false` it will avoid all shadow dom tests.
    * Defaults to `false`.
+   *
+   * @deprecated Since Stencil v3.0.0. IE 11, Edge <= 18, and old Safari versions
+   * are no longer supported.
    */
   __deprecated__shadowDomShim?: boolean;