--- a/browser/components/extensions/ext-tabs.js
+++ b/browser/components/extensions/ext-tabs.js
@@ -433,17 +433,20 @@ this.tabs = class extends ExtensionAPI {
 
           if (updateProperties.url !== null) {
             let url = context.uri.resolve(updateProperties.url);
 
             if (!context.checkLoadURL(url, {dontReportErrors: true})) {
               return Promise.reject({message: `Illegal URL: ${url}`});
             }
 
-            nativeTab.linkedBrowser.loadURI(url);
+            let flags = updateProperties.loadReplace
+              ? Ci.nsIWebNavigation.LOAD_FLAGS_REPLACE_HISTORY
+              : Ci.nsIWebNavigation.LOAD_FLAGS_NONE;
+            nativeTab.linkedBrowser.loadURIWithFlags(url, {flags});
           }
 
           if (updateProperties.active !== null) {
             if (updateProperties.active) {
               tabbrowser.selectedTab = nativeTab;
             } else {
               // Not sure what to do here? Which tab should we select?
             }

--- a/browser/components/extensions/schemas/tabs.json
+++ b/browser/components/extensions/schemas/tabs.json
@@ -743,16 +743,21 @@
                 "optional": true,
                 "description": "Whether the tab should be muted."
               },
               "openerTabId": {
                 "type": "integer",
                 "minimum": 0,
                 "optional": true,
                 "description": "The ID of the tab that opened this tab. If specified, the opener tab must be in the same window as this tab."
+              },
+              "loadReplace": {
+                "type": "boolean",
+                "optional": true,
+                "description": "Whether the load should replace the current history entry for the tab."
               }
             }
           },
           {
             "type": "function",
             "name": "callback",
             "optional": true,
             "parameters": [

--- a/browser/components/extensions/test/browser/browser_ext_tabs_update_url.js
+++ b/browser/components/extensions/test/browser/browser_ext_tabs_update_url.js
@@ -1,12 +1,17 @@
 /* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* vim: set sts=2 sw=2 et tw=80: */
 "use strict";
 
+XPCOMUtils.defineLazyModuleGetter(this, "SessionStore",
+                                  "resource:///modules/sessionstore/SessionStore.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "TabStateFlusher",
+                                  "resource:///modules/sessionstore/TabStateFlusher.jsm");
+
 async function testTabsUpdateURL(existentTabURL, tabsUpdateURL, isErrorExpected) {
   let extension = ExtensionTestUtils.loadExtension({
     manifest: {
       "permissions": ["tabs"],
     },
 
     files: {
       "tab.html": `
@@ -103,8 +108,78 @@ add_task(async function() {
         .map((check) => Object.assign({}, check, {existentTabURL: "about:blank"}));
 
   for (let {existentTabURL, tabsUpdateURL, isErrorExpected} of testCases) {
     await testTabsUpdateURL(existentTabURL, tabsUpdateURL, isErrorExpected);
   }
 
   info("done");
 });
+
+add_task(async function test_update_reload() {
+  const URL = "https://example.com/";
+
+  let extension = ExtensionTestUtils.loadExtension({
+    manifest: {
+      "permissions": ["tabs", "history"],
+    },
+
+    background() {
+      browser.test.onMessage.addListener(async (cmd, ...args) => {
+        const result = await browser.tabs[cmd](...args);
+        browser.test.sendMessage("result", result);
+      });
+
+      browser.history.onVisited.addListener(data => {
+        browser.test.sendMessage("historyAdded");
+      });
+    },
+  });
+
+  let win = await BrowserTestUtils.openNewBrowserWindow();
+  let tabBrowser = win.gBrowser.selectedBrowser;
+  await BrowserTestUtils.loadURI(tabBrowser, URL);
+  await BrowserTestUtils.browserLoaded(tabBrowser, false, URL);
+  let tab = win.gBrowser.selectedTab;
+
+  async function getTabHistory() {
+    await TabStateFlusher.flush(tabBrowser);
+    return JSON.parse(SessionStore.getTabState(tab));
+  }
+
+  await extension.startup();
+  extension.sendMessage("query", {url: URL});
+  let tabs = await extension.awaitMessage("result");
+  let tabId = tabs[0].id;
+
+  let history = await getTabHistory();
+  is(history.entries.length, 1,
+     "Tab history contains the expected number of entries.");
+  is(history.entries[0].url, URL,
+    `Tab history contains the expected entry: URL.`);
+
+  extension.sendMessage("update", tabId, {url: `${URL}1/`});
+  await Promise.all([
+    extension.awaitMessage("result"),
+    extension.awaitMessage("historyAdded"),
+  ]);
+
+  history = await getTabHistory();
+  is(history.entries.length, 2,
+     "Tab history contains the expected number of entries.");
+  is(history.entries[1].url, `${URL}1/`,
+    `Tab history contains the expected entry: ${URL}1/.`);
+
+  extension.sendMessage("update", tabId, {url: `${URL}2/`, loadReplace: true});
+  await Promise.all([
+    extension.awaitMessage("result"),
+    extension.awaitMessage("historyAdded"),
+  ]);
+
+  history = await getTabHistory();
+  is(history.entries.length, 2,
+     "Tab history contains the expected number of entries.");
+  is(history.entries[1].url, `${URL}2/`,
+    `Tab history contains the expected entry: ${URL}2/.`);
+
+  await extension.unload();
+  await BrowserTestUtils.closeWindow(win);
+});