diff --git a/README.md b/README.md
index b7ca61ba0..0bca574f1 100644
--- a/README.md
+++ b/README.md
@@ -198,7 +198,7 @@ if (process.env.NODE_ENV !== 'production') {
 }
 ```
 
-**IMPORTANT:** To use `__DEV__` in TypeScript, you need add `declare var __DEV__: boolean` somewhere in your project's type path (e.g. `./types/index.d.ts`).
+**IMPORTANT:** To use `__DEV__` in TypeScript, you need to add `declare var __DEV__: boolean` somewhere in your project's type path (e.g. `./types/index.d.ts`).
 
 ```ts
 // ./types/index.d.ts
diff --git a/website/pages/optimization.mdx b/website/pages/optimization.mdx
index dc12e9089..e837b4651 100644
--- a/website/pages/optimization.mdx
+++ b/website/pages/optimization.mdx
@@ -94,7 +94,7 @@ if (process.env.NODE_ENV !== 'production') {
 }
 ```
 
-**IMPORTANT:** To use `__DEV__` in TypeScript, you need add `declare var __DEV__: boolean` somewhere in your project's type path (e.g. `./types/index.d.ts`).
+**IMPORTANT:** To use `__DEV__` in TypeScript, you need to add `declare var __DEV__: boolean` somewhere in your project's type path (e.g. `./types/index.d.ts`).
 
 ```ts
 // ./types/index.d.ts