diff --git a/browser/base/content/tabbrowser.js b/browser/base/content/tabbrowser.js
index a32a1cc209f5..a042c5814809 100644
--- a/browser/base/content/tabbrowser.js
+++ b/browser/base/content/tabbrowser.js
@@ -2306,6 +2306,7 @@ window._gBrowser = {
     sameProcessAsFrameLoader,
     skipAnimation,
     skipBackgroundNotify,
+    title,
     triggeringPrincipal,
     userContextId,
     recordExecution,
@@ -2549,6 +2550,13 @@ window._gBrowser = {
                                                       userContextId);
           b.registeredOpenURI = lazyBrowserURI;
         }
+        SessionStore.setTabState(t, {
+          entries: [{
+            url: lazyBrowserURI ? lazyBrowserURI.spec : "about:blank",
+            title,
+            triggeringPrincipal_base64: Utils.serializePrincipal(triggeringPrincipal),
+          }],
+        });
       } else {
         this._insertBrowser(t, true);
       }
@@ -3809,12 +3817,15 @@ window._gBrowser = {
     // the same remote type and process as the one we're swapping in.
     // This makes sure we don't get a short-lived process for the new tab.
     let linkedBrowser = aTab.linkedBrowser;
+    let createLazyBrowser = !aTab.linkedPanel;
     let params = {
       eventDetail: { adoptedTab: aTab },
       preferredRemoteType: linkedBrowser.remoteType,
       sameProcessAsFrameLoader: linkedBrowser.frameLoader,
       skipAnimation: true,
       index: aIndex,
+      createLazyBrowser,
+      allowInheritPrincipal: createLazyBrowser,
     };
 
     let numPinned = this._numPinnedTabs;
@@ -3831,10 +3842,12 @@ window._gBrowser = {
 
     aTab.parentNode._finishAnimateTabMove();
 
-    // Stop the about:blank load.
-    newBrowser.stop();
-    // Make sure it has a docshell.
-    newBrowser.docShell;
+    if (!createLazyBrowser) {
+      // Stop the about:blank load.
+      newBrowser.stop();
+      // Make sure it has a docshell.
+      newBrowser.docShell;
+    }
 
     if (!this.swapBrowsersAndCloseOther(newTab, aTab)) {
       // Swapping wasn't permitted. Bail out.
diff --git a/browser/base/content/test/tabs/browser_multiselect_tabs_move_to_new_window_contextmenu.js b/browser/base/content/test/tabs/browser_multiselect_tabs_move_to_new_window_contextmenu.js
index 0ef998b315c8..bb4df30431be 100644
--- a/browser/base/content/test/tabs/browser_multiselect_tabs_move_to_new_window_contextmenu.js
+++ b/browser/base/content/test/tabs/browser_multiselect_tabs_move_to_new_window_contextmenu.js
@@ -44,3 +44,52 @@ add_task(async function test() {
   BrowserTestUtils.closeWindow(newWindow);
   BrowserTestUtils.removeTab(tab4);
 });
+
+add_task(async function testLazyTabs() {
+  let params = {createLazyBrowser: true};
+  let tabs = [];
+  let numTabs = 4;
+  for (let i = 0; i < numTabs; ++i) {
+    tabs.push(BrowserTestUtils.addTab(gBrowser, `http://example.com/?${i}`, params));
+  }
+
+  await BrowserTestUtils.switchTab(gBrowser, tabs[0]);
+  for (let i = 1; i < numTabs; ++i) {
+    await triggerClickOn(tabs[i], { ctrlKey: true });
+  }
+
+  isnot(tabs[0].linkedPanel, "", `Tab 0 shouldn't be lazy`);
+  for (let i = 1; i < numTabs; ++i) {
+    is(tabs[i].linkedPanel, "", `Tab ${i} should be lazy`);
+  }
+
+  is(gBrowser.multiSelectedTabsCount, numTabs, `${numTabs} multiselected tabs`);
+  for (let i = 0; i < numTabs; ++i) {
+    ok(tabs[i].multiselected, `Tab ${i} should be multiselected`);
+  }
+
+  let newWindow = gBrowser.replaceTabsWithWindow(tabs[0]);
+
+  await TestUtils.waitForCondition(() => newWindow.gBrowser, `Wait for gBrowser`);
+  await TestUtils.waitForCondition(() => newWindow.gBrowser.visibleTabs.length == numTabs,
+    `Wait for all ${numTabs} tabs to get moved to the new window`);
+  tabs = newWindow.gBrowser.tabs;
+
+  isnot(tabs[0].linkedPanel, "", `Tab 0 should continue not being lazy`);
+  // FIXME: bug 1521923 - First inactive tab to be moved into another window loses laziness
+  todo_is(tabs[1].linkedPanel, "", `Tab 1 should continue being lazy`);
+  for (let i = 2; i < numTabs; ++i) {
+    is(tabs[i].linkedPanel, "", `Tab ${i} should continue being lazy`);
+  }
+
+  is(tabs[0].linkedBrowser.currentURI.spec, `http://example.com/?0`,
+    `Tab 0 should have the right URL`);
+  todo_is(SessionStore.getLazyTabValue(tabs[1], "url"), `http://example.com/?1`,
+    `Tab 1 should have the right lazy URL`);
+  for (let i = 2; i < numTabs; ++i) {
+    is(SessionStore.getLazyTabValue(tabs[i], "url"), `http://example.com/?${i}`,
+      `Tab ${i} should have the right lazy URL`);
+  }
+
+  BrowserTestUtils.closeWindow(newWindow);
+});
diff --git a/browser/base/content/test/tabs/browser_multiselect_tabs_reopen_in_container.js b/browser/base/content/test/tabs/browser_multiselect_tabs_reopen_in_container.js
index 368d14dc84cb..1b5c91ea945b 100644
--- a/browser/base/content/test/tabs/browser_multiselect_tabs_reopen_in_container.js
+++ b/browser/base/content/test/tabs/browser_multiselect_tabs_reopen_in_container.js
@@ -56,7 +56,7 @@ add_task(async function testReopen() {
   let tab1 = await addTab("http://mochi.test:8888/1");
   let tab2 = await addTab("http://mochi.test:8888/2");
   let tab3 = await addTab("http://mochi.test:8888/3");
-  let tab4 = await addTab("http://mochi.test:8888/3", {createLazyBrowser: true});
+  let tab4 = BrowserTestUtils.addTab(gBrowser, "http://mochi.test:8888/3", {createLazyBrowser: true});
 
   await BrowserTestUtils.switchTab(gBrowser, tab1);
 
diff --git a/browser/components/extensions/parent/ext-tabs.js b/browser/components/extensions/parent/ext-tabs.js
index 72574f26124f..de2256c52d33 100644
--- a/browser/components/extensions/parent/ext-tabs.js
+++ b/browser/components/extensions/parent/ext-tabs.js
@@ -14,8 +14,6 @@ ChromeUtils.defineModuleGetter(this, "Services",
                                "resource://gre/modules/Services.jsm");
 ChromeUtils.defineModuleGetter(this, "SessionStore",
                                "resource:///modules/sessionstore/SessionStore.jsm");
-ChromeUtils.defineModuleGetter(this, "Utils",
-                               "resource://gre/modules/sessionstore/Utils.jsm");
 
 XPCOMUtils.defineLazyGetter(this, "strBundle", function() {
   return Services.strings.createBundle("chrome://global/locale/extensions.properties");
@@ -634,15 +632,6 @@ this.tabs = class extends ExtensionAPI {
 
             options.triggeringPrincipal = principal;
             let nativeTab = window.gBrowser.addTab(url, options);
-            if (createProperties.discarded) {
-              SessionStore.setTabState(nativeTab, {
-                entries: [{
-                  url: url,
-                  title: options.title,
-                  triggeringPrincipal_base64: Utils.serializePrincipal(principal),
-                }],
-              });
-            }
 
             if (active) {
               window.gBrowser.selectedTab = nativeTab;