--- a/browser/base/content/browser-sidebar.js
+++ b/browser/base/content/browser-sidebar.js
@@ -189,17 +189,17 @@ var SidebarUI = {
 
     // dynamically generated sidebars will fail this check, but we still
     // consider it adopted.
     if (!document.getElementById(commandID)) {
       return true;
     }
 
     this._box.setAttribute("width", sourceUI._box.boxObject.width);
-    this._show(commandID);
+    this.showInitially(commandID);
 
     return true;
   },
 
   windowPrivacyMatches(w1, w2) {
     return PrivateBrowsingUtils.isWindowPrivate(w1) === PrivateBrowsingUtils.isWindowPrivate(w2);
   },
 
@@ -224,17 +224,17 @@ var SidebarUI = {
 
     // If we're not adopting settings from a parent window, set them now.
     let commandID = this._box.getAttribute("sidebarcommand");
     if (!commandID) {
       return;
     }
 
     if (document.getElementById(commandID)) {
-      this._show(commandID);
+      this.showInitially(commandID);
     } else {
       // Remove the |sidebarcommand| attribute, because the element it
       // refers to no longer exists, so we should assume this sidebar
       // panel has been uninstalled. (249883)
       this._box.removeAttribute("sidebarcommand");
     }
   },
 
@@ -331,16 +331,27 @@ var SidebarUI = {
       }
 
       this._fireFocusedEvent();
       BrowserUITelemetry.countSidebarEvent(commandID, "show");
     });
   },
 
   /**
+   * Show the sidebar, without firing the focused event or logging telemetry.
+   * This is intended to be used when the sidebar is opened automatically
+   * when a window opens (not triggered by user interaction).
+   *
+   * @param {string} commandID ID of the xul:broadcaster element to use.
+   */
+   showInitially(commandID) {
+     return this._show(commandID);
+   },
+
+  /**
    * Implementation for show. Also used internally for sidebars that are shown
    * when a window is opened and we don't want to ping telemetry.
    *
    * @param {string} commandID ID of the xul:broadcaster element to use.
    */
   _show(commandID) {
     return new Promise((resolve, reject) => {
       let sidebarBroadcaster = this.getBroadcasterById(commandID);

--- a/browser/components/sessionstore/SessionStore.jsm
+++ b/browser/components/sessionstore/SessionStore.jsm
@@ -4082,17 +4082,17 @@ var SessionStoreInternal = {
           break;
         case "normal":
           aWindow.restore();
           break;
         }
       }
       var sidebar = aWindow.document.getElementById("sidebar-box");
       if (sidebar.getAttribute("sidebarcommand") != aSidebar) {
-        aWindow.SidebarUI.show(aSidebar);
+        aWindow.SidebarUI.showInitially(aSidebar);
       }
       // since resizing/moving a window brings it to the foreground,
       // we might want to re-focus the last focused window
       if (this.windowToFocus) {
         this.windowToFocus.focus();
       }
     } finally {
       // Enable animations.