--- a/browser/base/content/browser.js
+++ b/browser/base/content/browser.js
@@ -2368,28 +2368,32 @@ function BrowserViewSourceOfDocument(aAr
     args = { browser, outerWindowID, URL };
   } else {
     args = aArgsOrDocument;
   }
 
   let viewInternal = () => {
     let inTab = Services.prefs.getBoolPref("view_source.tab");
     if (inTab) {
-      let viewSourceURL = `view-source:${args.URL}`;
       let tabBrowser = gBrowser;
       // In the case of sidebars and chat windows, gBrowser is defined but null,
       // because no #content element exists.  For these cases, we need to find
       // the most recent browser window.
       // In the case of popups, we need to find a non-popup browser window.
       if (!tabBrowser || !window.toolbar.visible) {
         // This returns only non-popup browser windows by default.
         let browserWindow = RecentWindow.getMostRecentBrowserWindow();
         tabBrowser = browserWindow.gBrowser;
       }
-      let tab = tabBrowser.loadOneTab(viewSourceURL, {
+      // `viewSourceInBrowser` will load the source content from the page
+      // descriptor for the tab (when possible) or fallback to the network if
+      // that fails.  Either way, the view source module will manage the tab's
+      // location, so use "about:blank" here to avoid unnecessary redundant
+      // requests.
+      let tab = tabBrowser.loadOneTab("about:blank", {
         relatedToCurrent: true,
         inBackground: false
       });
       args.viewSourceBrowser = tabBrowser.getBrowserForTab(tab);
       top.gViewSourceUtils.viewSourceInBrowser(args);
     } else {
       top.gViewSourceUtils.viewSource(args);
     }