diff --git a/browser/actors/ContextMenuChild.jsm b/browser/actors/ContextMenuChild.jsm
index 26e2c90daf02..16a3f8ecbc81 100644
--- a/browser/actors/ContextMenuChild.jsm
+++ b/browser/actors/ContextMenuChild.jsm
@@ -1227,4 +1227,20 @@ class ContextMenuChild extends JSWindowActorChild {
       }
     }
   }
+
+  _destructionObservers = new Set();
+  registerDestructionObserver(obj) {
+    this._destructionObservers.add(obj);
+  }
+
+  unregisterDestructionObserver(obj) {
+    this._destructionObservers.delete(obj);
+  }
+
+  didDestroy() {
+    for (let obs of this._destructionObservers) {
+      obs.actorDestroyed(this);
+    }
+    this._destructionObservers = null;
+  }
 }
diff --git a/browser/base/content/test/contextMenu/browser.ini b/browser/base/content/test/contextMenu/browser.ini
index f715e426c39b..f0a208793d63 100644
--- a/browser/base/content/test/contextMenu/browser.ini
+++ b/browser/base/content/test/contextMenu/browser.ini
@@ -16,6 +16,8 @@ support-files =
 
 [browser_contextmenu_loadblobinnewtab.js]
 support-files = browser_contextmenu_loadblobinnewtab.html
+[browser_contextmenu_spellcheck.js]
+skip-if = toolkit == "gtk" || (os == "win" && processor == "aarch64") # disabled on Linux due to bug 513558, aarch64 due to 1533161
 [browser_view_image.js]
 support-files =
   test_view_image_revoked_cached_blob.html
diff --git a/browser/base/content/test/contextMenu/browser_contextmenu_input.js b/browser/base/content/test/contextMenu/browser_contextmenu_input.js
index 6e30b0580f1b..94e9465fd58c 100644
--- a/browser/base/content/test/contextMenu/browser_contextmenu_input.js
+++ b/browser/base/content/test/contextMenu/browser_contextmenu_input.js
@@ -45,146 +45,6 @@ add_task(async function test_text_input() {
   ]);
 });
 
-add_task(async function test_text_input_spellcheck() {
-  await test_contextmenu(
-    "#input_spellcheck_no_value",
-    [
-      "context-undo",
-      false,
-      "---",
-      null,
-      "context-cut",
-      true,
-      "context-copy",
-      true,
-      "context-paste",
-      null, // ignore clipboard state
-      "context-delete",
-      false,
-      "---",
-      null,
-      "context-selectall",
-      false,
-      "---",
-      null,
-      "spell-check-enabled",
-      true,
-      "spell-dictionaries",
-      true,
-      [
-        "spell-check-dictionary-en-US",
-        true,
-        "---",
-        null,
-        "spell-add-dictionaries",
-        true,
-      ],
-      null,
-    ],
-    {
-      waitForSpellCheck: true,
-      async preCheckContextMenuFn() {
-        await SpecialPowers.spawn(
-          gBrowser.selectedBrowser,
-          [],
-          async function() {
-            let doc = content.document;
-            let input = doc.getElementById("input_spellcheck_no_value");
-            input.setAttribute("spellcheck", "true");
-            input.clientTop; // force layout flush
-          }
-        );
-      },
-    }
-  );
-});
-
-add_task(async function test_text_input_spellcheckwrong() {
-  await test_contextmenu(
-    "#input_spellcheck_incorrect",
-    [
-      "*prodigality",
-      true, // spelling suggestion
-      "spell-add-to-dictionary",
-      true,
-      "---",
-      null,
-      "context-undo",
-      false,
-      "---",
-      null,
-      "context-cut",
-      true,
-      "context-copy",
-      true,
-      "context-paste",
-      null, // ignore clipboard state
-      "context-delete",
-      false,
-      "---",
-      null,
-      "context-selectall",
-      true,
-      "---",
-      null,
-      "spell-check-enabled",
-      true,
-      "spell-dictionaries",
-      true,
-      [
-        "spell-check-dictionary-en-US",
-        true,
-        "---",
-        null,
-        "spell-add-dictionaries",
-        true,
-      ],
-      null,
-    ],
-    { waitForSpellCheck: true }
-  );
-});
-
-add_task(async function test_text_input_spellcheckcorrect() {
-  await test_contextmenu(
-    "#input_spellcheck_correct",
-    [
-      "context-undo",
-      false,
-      "---",
-      null,
-      "context-cut",
-      true,
-      "context-copy",
-      true,
-      "context-paste",
-      null, // ignore clipboard state
-      "context-delete",
-      false,
-      "---",
-      null,
-      "context-selectall",
-      true,
-      "---",
-      null,
-      "spell-check-enabled",
-      true,
-      "spell-dictionaries",
-      true,
-      [
-        "spell-check-dictionary-en-US",
-        true,
-        "---",
-        null,
-        "spell-add-dictionaries",
-        true,
-      ],
-      null,
-    ],
-    { waitForSpellCheck: true }
-  );
-});
-
 add_task(async function test_text_input_disabled() {
   await test_contextmenu(
     "#input_disabled",
@@ -204,7 +64,7 @@ add_task(async function test_text_input_disabled() {
       "---",
       null,
       "context-selectall",
-      true,
+      false,
       "---",
       null,
       "spell-check-enabled",
diff --git a/browser/base/content/test/contextMenu/browser_contextmenu_spellcheck.js b/browser/base/content/test/contextMenu/browser_contextmenu_spellcheck.js
new file mode 100644
index 000000000000..3a150fecffad
--- /dev/null
+++ b/browser/base/content/test/contextMenu/browser_contextmenu_spellcheck.js
@@ -0,0 +1,251 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+let contextMenu;
+
+const example_base =
+  "http://example.com/browser/browser/base/content/test/contextMenu/";
+const MAIN_URL = example_base + "subtst_contextmenu_input.html";
+
+add_task(async function test_setup() {
+  await BrowserTestUtils.openNewForegroundTab(gBrowser, MAIN_URL);
+
+  const chrome_base =
+    "chrome://mochitests/content/browser/browser/base/content/test/contextMenu/";
+  const contextmenu_common = chrome_base + "contextmenu_common.js";
+  /* import-globals-from contextmenu_common.js */
+  Services.scriptloader.loadSubScript(contextmenu_common, this);
+
+  // Ensure screenshots is really disabled (bug 1498738)
+  const addon = await AddonManager.getAddonByID("screenshots@mozilla.org");
+  await addon.disable({ allowSystemAddons: true });
+});
+
+add_task(async function test_text_input_spellcheck() {
+  await test_contextmenu(
+    "#input_spellcheck_no_value",
+    [
+      "context-undo",
+      false,
+      "---",
+      null,
+      "context-cut",
+      null, // ignore the enabled/disabled states; there are race conditions
+      // in the edit commands but they're not relevant for what we're testing.
+      "context-copy",
+      null,
+      "context-paste",
+      null, // ignore clipboard state
+      "context-delete",
+      null,
+      "---",
+      null,
+      "context-selectall",
+      null,
+      "---",
+      null,
+      "spell-check-enabled",
+      true,
+      "spell-dictionaries",
+      true,
+      [
+        "spell-check-dictionary-en-US",
+        true,
+        "---",
+        null,
+        "spell-add-dictionaries",
+        true,
+      ],
+      null,
+    ],
+    {
+      waitForSpellCheck: true,
+      async preCheckContextMenuFn() {
+        await SpecialPowers.spawn(
+          gBrowser.selectedBrowser,
+          [],
+          async function() {
+            let doc = content.document;
+            let input = doc.getElementById("input_spellcheck_no_value");
+            input.setAttribute("spellcheck", "true");
+            input.clientTop; // force layout flush
+          }
+        );
+      },
+    }
+  );
+});
+
+add_task(async function test_text_input_spellcheckwrong() {
+  await test_contextmenu(
+    "#input_spellcheck_incorrect",
+    [
+      "*prodigality",
+      true, // spelling suggestion
+      "spell-add-to-dictionary",
+      true,
+      "---",
+      null,
+      "context-undo",
+      null,
+      "---",
+      null,
+      "context-cut",
+      null,
+      "context-copy",
+      null,
+      "context-paste",
+      null, // ignore clipboard state
+      "context-delete",
+      null,
+      "---",
+      null,
+      "context-selectall",
+      null,
+      "---",
+      null,
+      "spell-check-enabled",
+      true,
+      "spell-dictionaries",
+      true,
+      [
+        "spell-check-dictionary-en-US",
+        true,
+        "---",
+        null,
+        "spell-add-dictionaries",
+        true,
+      ],
+      null,
+    ],
+    { waitForSpellCheck: true }
+  );
+});
+
+const kCorrectItems = [
+  "context-undo",
+  false,
+  "---",
+  null,
+  "context-cut",
+  null,
+  "context-copy",
+  null,
+  "context-paste",
+  null, // ignore clipboard state
+  "context-delete",
+  null,
+  "---",
+  null,
+  "context-selectall",
+  null,
+  "---",
+  null,
+  "spell-check-enabled",
+  true,
+  "spell-dictionaries",
+  true,
+  [
+    "spell-check-dictionary-en-US",
+    true,
+    "---",
+    null,
+    "spell-add-dictionaries",
+    true,
+  ],
+  null,
+];
+
+add_task(async function test_text_input_spellcheckcorrect() {
+  await test_contextmenu("#input_spellcheck_correct", kCorrectItems, {
+    waitForSpellCheck: true,
+  });
+});
+
+add_task(async function test_text_input_spellcheck_deadactor() {
+  await test_contextmenu("#input_spellcheck_correct", kCorrectItems, {
+    waitForSpellCheck: true,
+    keepMenuOpen: true,
+  });
+  let wgp = gBrowser.selectedBrowser.browsingContext.currentWindowGlobal;
+
+  // Now the menu is open, and spellcheck is running, switch to another tab and
+  // close the original:
+  let tab = gBrowser.selectedTab;
+  await BrowserTestUtils.openNewForegroundTab(gBrowser, "https://example.org");
+  BrowserTestUtils.removeTab(tab);
+  // Ensure we've invalidated the actor
+  await TestUtils.waitForCondition(
+    () => wgp.isClosed,
+    "Waiting for actor to be dead after tab closes"
+  );
+  contextMenu.hidePopup();
+
+  // Now go back to the input testcase:
+  BrowserTestUtils.loadURI(gBrowser.selectedBrowser, MAIN_URL);
+  await BrowserTestUtils.browserLoaded(
+    gBrowser.selectedBrowser,
+    false,
+    MAIN_URL
+  );
+
+  // Check the menu still looks the same, keep it open again:
+  await test_contextmenu("#input_spellcheck_correct", kCorrectItems, {
+    waitForSpellCheck: true,
+    keepMenuOpen: true,
+  });
+
+  // Now navigate the tab, after ensuring there's an unload listener, so
+  // we don't end up in bfcache:
+  await SpecialPowers.spawn(gBrowser.selectedBrowser, [], async function() {
+    content.document.body.setAttribute("onunload", "");
+  });
+  wgp = gBrowser.selectedBrowser.browsingContext.currentWindowGlobal;
+
+  const NEW_URL = MAIN_URL.replace(".com", ".org");
+  BrowserTestUtils.loadURI(gBrowser.selectedBrowser, NEW_URL);
+  await BrowserTestUtils.browserLoaded(
+    gBrowser.selectedBrowser,
+    false,
+    NEW_URL
+  );
+  // Ensure we've invalidated the actor
+  await TestUtils.waitForCondition(
+    () => wgp.isClosed,
+    "Waiting for actor to be dead after onunload"
+  );
+  contextMenu.hidePopup();
+
+  // Check the menu *still* looks the same (and keep it open again):
+  await test_contextmenu("#input_spellcheck_correct", kCorrectItems, {
+    waitForSpellCheck: true,
+    keepMenuOpen: true,
+  });
+
+  // Check what happens if the actor stays alive by loading the same page
+  // again; now the context menu stuff should be destroyed by the menu
+  // hiding, nothing else.
+  wgp = gBrowser.selectedBrowser.browsingContext.currentWindowGlobal;
+  BrowserTestUtils.loadURI(gBrowser.selectedBrowser, NEW_URL);
+  await BrowserTestUtils.browserLoaded(
+    gBrowser.selectedBrowser,
+    false,
+    NEW_URL
+  );
+  contextMenu.hidePopup();
+
+  // Check the menu still looks the same:
+  await test_contextmenu("#input_spellcheck_correct", kCorrectItems, {
+    waitForSpellCheck: true,
+  });
+  // And test it a last time without any navigation:
+  await test_contextmenu("#input_spellcheck_correct", kCorrectItems, {
+    waitForSpellCheck: true,
+  });
+});
+
+add_task(async function test_cleanup() {
+  BrowserTestUtils.removeTab(gBrowser.selectedTab);
+});
diff --git a/browser/base/content/test/contextMenu/contextmenu_common.js b/browser/base/content/test/contextMenu/contextmenu_common.js
index e881ba5ef6dd..5ffb84f84931 100644
--- a/browser/base/content/test/contextMenu/contextmenu_common.js
+++ b/browser/base/content/test/contextMenu/contextmenu_common.js
@@ -352,6 +352,8 @@ let lastElementSelector = null;
  *        preCheckContextMenuFn: callback to run before opening menu
  *        onContextMenuShown: callback to run when the context menu is shown
  *        postCheckContextMenuFn: callback to run after opening menu
+ *        keepMenuOpen: if true, we do not call hidePopup, the consumer is
+ *                      responsible for calling it.
  * @return {Promise} resolved after the test finishes
  */
 async function test_contextmenu(selector, menuItems, options = {}) {
@@ -472,6 +474,8 @@ async function test_contextmenu(selector, menuItems, options = {}) {
     info("Completed postCheckContextMenuFn");
   }
 
-  contextMenu.hidePopup();
-  await awaitPopupHidden;
+  if (!options.keepMenuOpen) {
+    contextMenu.hidePopup();
+    await awaitPopupHidden;
+  }
 }
diff --git a/toolkit/actors/InlineSpellCheckerParent.jsm b/toolkit/actors/InlineSpellCheckerParent.jsm
index 755a9215ede9..84b8a616cc43 100644
--- a/toolkit/actors/InlineSpellCheckerParent.jsm
+++ b/toolkit/actors/InlineSpellCheckerParent.jsm
@@ -28,6 +28,25 @@ class InlineSpellCheckerParent extends JSWindowActorParent {
   }
 
   uninit() {
+    // This method gets called by InlineSpellChecker when the context menu
+    // goes away and the InlineSpellChecker instance is still alive.
+    // Stop referencing it and tidy the child end of us.
     this.sendAsyncMessage("InlineSpellChecker:uninit", {});
   }
+
+  _destructionObservers = new Set();
+  registerDestructionObserver(obj) {
+    this._destructionObservers.add(obj);
+  }
+
+  unregisterDestructionObserver(obj) {
+    this._destructionObservers.delete(obj);
+  }
+
+  didDestroy() {
+    for (let obs of this._destructionObservers) {
+      obs.actorDestroyed(this);
+    }
+    this._destructionObservers = null;
+  }
 }
diff --git a/toolkit/modules/InlineSpellChecker.jsm b/toolkit/modules/InlineSpellChecker.jsm
index 23dff64056a7..ffc58714b0d9 100644
--- a/toolkit/modules/InlineSpellChecker.jsm
+++ b/toolkit/modules/InlineSpellChecker.jsm
@@ -27,7 +27,15 @@ InlineSpellChecker.prototype = {
 
   initFromRemote(aSpellInfo, aWindowGlobalParent) {
     if (this.mRemote) {
-      throw new Error("Unexpected state");
+      // We shouldn't get here, but let's just recover instead of bricking the
+      // menu by throwing exceptions:
+      Cu.reportError(new Error("Unexpected remote spellchecker present!"));
+      try {
+        this.mRemote.uninit();
+      } catch (ex) {
+        Cu.reportError(ex);
+      }
+      this.mRemote = null;
     }
     this.uninit();
 
@@ -490,6 +498,7 @@ function RemoteSpellChecker(aSpellInfo, aWindowGlobalParent) {
   this._spellInfo = aSpellInfo;
   this._suggestionGenerator = null;
   this._actor = aWindowGlobalParent.getActor("InlineSpellChecker");
+  this._actor.registerDestructionObserver(this);
 }
 
 RemoteSpellChecker.prototype = {
@@ -571,6 +580,15 @@ RemoteSpellChecker.prototype = {
     this._actor.recheckSpelling();
   },
   uninit() {
-    this._actor.uninit();
+    if (this._actor) {
+      this._actor.uninit();
+      this._actor.unregisterDestructionObserver(this);
+    }
+  },
+
+  actorDestroyed() {
+    // The actor lets us know if it gets destroyed, so we don't
+    // later try to call `.uninit()` on it.
+    this._actor = null;
   },
 };
diff --git a/toolkit/modules/InlineSpellCheckerContent.jsm b/toolkit/modules/InlineSpellCheckerContent.jsm
index 7284dca69003..205585c4543f 100644
--- a/toolkit/modules/InlineSpellCheckerContent.jsm
+++ b/toolkit/modules/InlineSpellCheckerContent.jsm
@@ -17,6 +17,7 @@ var InlineSpellCheckerContent = {
 
   initContextMenu(event, editFlags, actor) {
     this._actor = actor;
+    this._actor.registerDestructionObserver(this);
 
     let spellChecker;
     if (!(editFlags & (SpellCheckHelper.TEXTAREA | SpellCheckHelper.INPUT))) {
@@ -75,10 +76,17 @@ var InlineSpellCheckerContent = {
   },
 
   uninitContextMenu() {
+    if (this._actor) {
+      this._actor.unregisterDestructionObserver(this);
+    }
     this._actor = null;
     this._spellChecker = null;
   },
 
+  actorDestroyed() {
+    this.uninitContextMenu();
+  },
+
   _generateSpellSuggestions() {
     let spellChecker = this._spellChecker.mInlineSpellChecker.spellChecker;
     try {