diff --git a/src/common/Browser.ts b/src/common/Browser.ts
index f1df577275241..cbb3932d8605c 100644
--- a/src/common/Browser.ts
+++ b/src/common/Browser.ts
@@ -480,7 +480,7 @@ export class Browser extends EventEmitter {
     const { timeout = 30000 } = options;
     const existingTarget = this.targets().find(predicate);
     if (existingTarget) return existingTarget;
-    let resolve;
+    let resolve: (value: Target | PromiseLike<Target>) => void;
     const targetPromise = new Promise<Target>((x) => (resolve = x));
     this.on(BrowserEmittedEvents.TargetCreated, check);
     this.on(BrowserEmittedEvents.TargetChanged, check);
diff --git a/src/common/Page.ts b/src/common/Page.ts
index 238d7bde360d5..d342f18929695 100644
--- a/src/common/Page.ts
+++ b/src/common/Page.ts
@@ -641,7 +641,7 @@ export class Page extends EventEmitter {
       });
 
     const { timeout = this._timeoutSettings.timeout() } = options;
-    let callback;
+    let callback: (value: FileChooser | PromiseLike<FileChooser>) => void;
     const promise = new Promise<FileChooser>((x) => (callback = x));
     this._fileChooserInterceptors.add(callback);
     return helper