diff --git a/browser/modules/PageActions.jsm b/browser/modules/PageActions.jsm
index ca54fe333237..99c92e0d0638 100644
--- a/browser/modules/PageActions.jsm
+++ b/browser/modules/PageActions.jsm
@@ -224,6 +224,7 @@ this.PageActions = {
         this._persistedActions.idsInUrlbar.includes(action.id);
     } else {
       // The action is new.  Store it in the persisted actions.
+      this._persistedActions.ids.push(action.id);
       this._updateIDsInUrlbarForAction(action);
     }
   },
diff --git a/browser/modules/test/browser/browser_PageActions.js b/browser/modules/test/browser/browser_PageActions.js
index c051113c5691..b805dd87a36e 100644
--- a/browser/modules/test/browser/browser_PageActions.js
+++ b/browser/modules/test/browser/browser_PageActions.js
@@ -109,6 +109,9 @@ add_task(async function simple() {
   Assert.deepEqual(PageActions.actionForID(action.id), action,
                    "actionForID should be action");
 
+  Assert.ok(PageActions._persistedActions.ids.includes(action.id),
+            "PageActions should record action in its list of seen actions");
+
   // The action's panel button should have been created.
   let panelButtonNode = document.getElementById(panelButtonID);
   Assert.notEqual(panelButtonNode, null, "panelButtonNode");
@@ -179,6 +182,29 @@ add_task(async function simple() {
   Assert.equal(action.title, newTitle, "New title");
   Assert.equal(panelButtonNode.getAttribute("label"), action.title, "New label");
 
+  // Now that shownInUrlbar has been toggled, make sure that it sticks across
+  // app restarts.  Simulate that by "unregistering" the action (not by removing
+  // it, which is more permanent) and then registering it again.
+
+  // unregister
+  PageActions._actionsByID.delete(action.id);
+  let index = PageActions._nonBuiltInActions.findIndex(a => a.id == action.id);
+  Assert.ok(index >= 0, "Action should be in _nonBuiltInActions to begin with");
+  PageActions._nonBuiltInActions.splice(index, 1);
+
+  // register again
+  PageActions._registerAction(action);
+
+  // check relevant properties
+  Assert.ok(PageActions._persistedActions.ids.includes(action.id),
+            "PageActions should have 'seen' the action");
+  Assert.ok(PageActions._persistedActions.idsInUrlbar.includes(action.id),
+            "idsInUrlbar should still include the action");
+  Assert.ok(action.shownInUrlbar,
+            "shownInUrlbar should still be true");
+  Assert.ok(action._shownInUrlbar,
+            "_shownInUrlbar should still be true, for good measure");
+
   // Remove the action.
   action.remove();
   panelButtonNode = document.getElementById(panelButtonID);
@@ -191,6 +217,9 @@ add_task(async function simple() {
   Assert.equal(PageActions.actionForID(action.id), null,
                "actionForID should be null");
 
+  Assert.ok(!PageActions._persistedActions.ids.includes(action.id),
+            "PageActions should remove action from its list of seen actions");
+
   // The separator between the built-in actions and non-built-in actions should
   // be gone now, too.
   let separatorNode = document.getElementById(