diff --git a/CHANGELIST.md b/CHANGELIST.md
index 11e658c..47a80f5 100644
--- a/CHANGELIST.md
+++ b/CHANGELIST.md
@@ -4,6 +4,7 @@
 
 - [#488](https://github.com/nevware21/ts-async/issues/488) [CHORE] Drop Node.js 16 from CI matrix and add Node.js 24
   - Node.js 16 is end-of-life and is no longer supported by key tooling dependencies (for example `puppeteer` and `@pnpm/error` require Node.js >= 18)
+- [#499](https://github.com/nevware21/ts-async/issues/499) [BUG] Add the required ES Promise / Iterable / AsyncIterable libs to the package tsconfig and document the consumer ES2018 lib requirement
 
 # v0.5.5 Jan 5th, 2026
 
diff --git a/README.md b/README.md
index 635d022..3b3a773 100644
--- a/README.md
+++ b/README.md
@@ -101,6 +101,11 @@ Install the npm packare: `npm install @nevware21/ts-async --save`
 > "@nevware21/ts-async": ">= 0.5.5 < 2.x"
 > ```
 
+This package still targets ES5 at runtime, but its public TypeScript types use later built-in definitions such as `Promise`, `Iterable`, and `AsyncIterable`. If your project currently compiles with only ES5 libs, update your `tsconfig.json` to include a later ES lib, for example:
+
+- Browser / mixed environments: `"lib": ["ES2018", "DOM"]`
+- Node-only environments: `"lib": ["ES2018"]`
+
 And then just import the helpers and use them.
 
 ### Simple Examples
diff --git a/common/config/rush/npm-shrinkwrap.json b/common/config/rush/npm-shrinkwrap.json
index e5f47f3..da55f6c 100644
--- a/common/config/rush/npm-shrinkwrap.json
+++ b/common/config/rush/npm-shrinkwrap.json
@@ -3012,9 +3012,9 @@
       "integrity": "sha512-WMwm9LhRUo+WUaRN+vRuETqG89IgZphVSNkdFgeb6sS/E4OrDIN7t48CAewSHXc6C8lefD8KKfr5vY61brQlow=="
     },
     "node_modules/electron-to-chromium": {
-      "version": "1.5.359",
-      "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.5.359.tgz",
-      "integrity": "sha512-8lPELWuYZIWk7NDvCNthtmMw/7Q5Wu25NpM4djFMHBmk8DubPAtL4YTOp7ou0e7HyJtwkVlWv8XMLURnrtgJQw=="
+      "version": "1.5.360",
+      "resolved": "https://registry.npmjs.org/electron-to-chromium/-/electron-to-chromium-1.5.360.tgz",
+      "integrity": "sha512-GkcBt6YYAw9SxFWn+xVar4cLVGlXVuswwtRLBozi2zp0GjXs4ZnOrqV4zbXzg35n7w81hCkyJNYicgXlVHAmBA=="
     },
     "node_modules/elliptic": {
       "version": "6.6.1",
@@ -6385,9 +6385,9 @@
       }
     },
     "node_modules/path-scurry/node_modules/lru-cache": {
-      "version": "11.4.0",
-      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-11.4.0.tgz",
-      "integrity": "sha512-W+R+kFL4HgVxONq2bhXPi3bGpzGe/yEhVOp233qw9wCRtgncJ15P3bC+e4zZMu4Cq7d+WAJjXGW0uUkifhcatA==",
+      "version": "11.5.0",
+      "resolved": "https://registry.npmjs.org/lru-cache/-/lru-cache-11.5.0.tgz",
+      "integrity": "sha512-5YgH9UJd7wVb9hIouI2adWpgqrrICkt070Dnj8EUY1+B4B2P9eRLPAkAAo6NICA7CEhOIeBHl46u9zSNpNu7zA==",
       "engines": {
         "node": "20 || >=22"
       }
diff --git a/lib/tsconfig.es6.json b/lib/tsconfig.es6.json
index e079dfa..9976723 100644
--- a/lib/tsconfig.es6.json
+++ b/lib/tsconfig.es6.json
@@ -1,7 +1,12 @@
 {
     "extends": "./tsconfig.base.json",
     "compilerOptions": {
+        "lib": [
+            "dom",
+            "es6",
+            "es2018.asynciterable"
+        ],
         "target": "es6",
         "outDir": "./build/es6"
     }
-}
\ No newline at end of file
+}
diff --git a/lib/tsconfig.json b/lib/tsconfig.json
index 6b9580d..b8f9fe8 100644
--- a/lib/tsconfig.json
+++ b/lib/tsconfig.json
@@ -1,10 +1,16 @@
 {
     "extends": "./tsconfig.base.json",
     "compilerOptions": {
+        "lib": [
+            "dom",
+            "es2015.promise",
+            "es2015.iterable",
+            "es2018.asynciterable"
+        ],
         "target": "es5",
         "declaration": true,
         "declarationDir": "./build/types",
         "removeComments": false,
         "outDir": "./build/es5"
     }
-}
\ No newline at end of file
+}