diff --git a/lib/NetworkManager.js b/lib/NetworkManager.js
index 79263cd9..93382dad 100644
--- a/lib/NetworkManager.js
+++ b/lib/NetworkManager.js
@@ -16,7 +16,6 @@
 const EventEmitter = require('events');
 const {helper, assert, debugError} = require('./helper');
 const {Events} = require('./Events');
-const Multimap = require('./Multimap');
 
 class NetworkManager extends EventEmitter {
   /**
@@ -41,10 +40,8 @@ class NetworkManager extends EventEmitter {
     this._attemptedAuthentications = new Set();
     this._userRequestInterceptionEnabled = false;
     this._protocolRequestInterceptionEnabled = false;
-    /** @type {!Multimap<string, string>} */
-    this._requestHashToRequestIds = new Multimap();
-    /** @type {!Multimap<string, string>} */
-    this._requestHashToInterceptionIds = new Multimap();
+    /** @type {!Map<string, string>} */
+    this._requestIdToInterceptionId = new Map();
 
     this._client.on('Network.requestWillBeSent', this._onRequestWillBeSent.bind(this));
     this._client.on('Network.requestIntercepted', this._onRequestIntercepted.bind(this));
@@ -138,13 +135,12 @@ class NetworkManager extends EventEmitter {
   _onRequestWillBeSent(event) {
     // Request interception doesn't happen for data URLs with Network Service.
     if (this._protocolRequestInterceptionEnabled && !event.request.url.startsWith('data:')) {
-      const requestHash = generateRequestHash(event.request);
-      const interceptionId = this._requestHashToInterceptionIds.firstValue(requestHash);
+      const requestId = event.requestId;
+      const interceptionId = this._requestIdToInterceptionId.get(requestId);
       if (interceptionId) {
         this._onRequest(event, interceptionId);
-        this._requestHashToInterceptionIds.delete(requestHash, interceptionId);
+        this._requestIdToInterceptionId.delete(requestId);
       } else {
-        this._requestHashToRequestIds.set(requestHash, event.requestId);
         this._requestIdToRequestWillBeSentEvent.set(event.requestId, event);
       }
       return;
@@ -178,15 +174,13 @@ class NetworkManager extends EventEmitter {
       }).catch(debugError);
     }
 
-    const requestHash = generateRequestHash(event.request);
-    const requestId = this._requestHashToRequestIds.firstValue(requestHash);
-    if (requestId) {
+    const requestId = event.requestId;
+    if (requestId && this._requestIdToRequestWillBeSentEvent.has(requestId)) {
       const requestWillBeSentEvent = this._requestIdToRequestWillBeSentEvent.get(requestId);
       this._onRequest(requestWillBeSentEvent, event.interceptionId);
-      this._requestHashToRequestIds.delete(requestHash, requestId);
       this._requestIdToRequestWillBeSentEvent.delete(requestId);
     } else {
-      this._requestHashToInterceptionIds.set(requestHash, event.interceptionId);
+      this._requestIdToInterceptionId.set(requestId, event.interceptionId);
     }
   }
 
@@ -648,42 +642,6 @@ class Response {
   }
 }
 
-const IGNORED_HEADERS = new Set(['accept', 'referer', 'x-devtools-emulate-network-conditions-client-id', 'cookie', 'origin', 'content-type', 'intervention']);
-
-/**
- * @param {!Protocol.Network.Request} request
- * @return {string}
- */
-function generateRequestHash(request) {
-  let normalizedURL = request.url;
-  try {
-    // Decoding is necessary to normalize URLs. @see crbug.com/759388
-    // The method will throw if the URL is malformed. In this case,
-    // consider URL to be normalized as-is.
-    normalizedURL = decodeURI(request.url);
-  } catch (e) {
-  }
-  const hash = {
-    url: normalizedURL,
-    method: request.method,
-    postData: request.postData,
-    headers: {},
-  };
-
-  if (!normalizedURL.startsWith('data:')) {
-    const headers = Object.keys(request.headers);
-    headers.sort();
-    for (let header of headers) {
-      const headerValue = request.headers[header];
-      header = header.toLowerCase();
-      if (IGNORED_HEADERS.has(header))
-        continue;
-      hash.headers[header] = headerValue;
-    }
-  }
-  return JSON.stringify(hash);
-}
-
 class SecurityDetails {
   /**
    * @param {!Protocol.Network.SecurityDetails} securityPayload
diff --git a/test/network.spec.js b/test/network.spec.js
index 280730fb..996f8f0e 100644
--- a/test/network.spec.js
+++ b/test/network.spec.js
@@ -412,7 +412,7 @@ module.exports.addTests = function({testRunner, expect, CHROME}) {
       ]);
     });
     // @see https://github.com/GoogleChrome/puppeteer/issues/3973
-    xit('should work when header manipulation headers with redirect', async({page, server}) => {
+    it('should work when header manipulation headers with redirect', async({page, server}) => {
       server.setRedirect('/rrredirect', '/empty.html');
       await page.setRequestInterception(true);
       page.on('request', request => {