diff --git a/packages/playwright-core/src/client/fetch.ts b/packages/playwright-core/src/client/fetch.ts
index 58928532ac..efacce417d 100644
--- a/packages/playwright-core/src/client/fetch.ts
+++ b/packages/playwright-core/src/client/fetch.ts
@@ -416,8 +416,10 @@ function objectToArray(map?: { [key: string]: any }): NameValue[] | undefined {
   if (!map)
     return undefined;
   const result = [];
-  for (const [name, value] of Object.entries(map))
-    result.push({ name, value: String(value) });
+  for (const [name, value] of Object.entries(map)) {
+    if (value !== undefined)
+      result.push({ name, value: String(value) });
+  }
   return result;
 }
 
diff --git a/tests/library/browsercontext-fetch.spec.ts b/tests/library/browsercontext-fetch.spec.ts
index 38848dd497..f23b59f97c 100644
--- a/tests/library/browsercontext-fetch.spec.ts
+++ b/tests/library/browsercontext-fetch.spec.ts
@@ -1183,7 +1183,7 @@ it('should send secure cookie over http for localhost', async ({ page, server })
   expect(serverRequest.headers.cookie).toBe('a=v');
 });
 
-it('should accept bool and numeric params', async ({ page, server }) => {
+it('should accept bool and numeric params and filter out undefined', async ({ page, server }) => {
   let request;
   const url = new URL(server.EMPTY_PAGE);
   url.searchParams.set('str', 's');
@@ -1200,6 +1200,7 @@ it('should accept bool and numeric params', async ({ page, server }) => {
       'num': 10,
       'bool': true,
       'bool2': false,
+      'none': undefined,
     }
   });
   const params = new URLSearchParams(request!.url.substr(request!.url.indexOf('?')));
@@ -1207,6 +1208,7 @@ it('should accept bool and numeric params', async ({ page, server }) => {
   expect(params.get('num')).toEqual('10');
   expect(params.get('bool')).toEqual('true');
   expect(params.get('bool2')).toEqual('false');
+  expect(params.has('none')).toBe(false);
 });
 
 it('should abort requests when browser context closes', async ({ contextFactory, server }) => {