diff --git a/browser/base/content/test/sanitize/browser.ini b/browser/base/content/test/sanitize/browser.ini
index 15003c85889a..72557f4b0d9a 100644
--- a/browser/base/content/test/sanitize/browser.ini
+++ b/browser/base/content/test/sanitize/browser.ini
@@ -11,9 +11,6 @@ support-files=
 [browser_sanitize-sitepermissions.js]
 [browser_sanitize-timespans.js]
 [browser_sanitizeDialog.js]
-prefs=
-  browser.cache.offline.enable=true
-  browser.cache.offline.storage.enable=true
 [browser_cookiePermission.js]
 [browser_cookiePermission_aboutURL.js]
 [browser_cookiePermission_containers.js]
diff --git a/browser/base/content/test/sanitize/browser_sanitizeDialog.js b/browser/base/content/test/sanitize/browser_sanitizeDialog.js
index 0649c54f5d8c..bc4aa6a0f0f3 100644
--- a/browser/base/content/test/sanitize/browser_sanitizeDialog.js
+++ b/browser/base/content/test/sanitize/browser_sanitizeDialog.js
@@ -490,6 +490,8 @@ add_task(async function test_form_entries() {
 
 // Test for offline cache deletion
 add_task(async function test_offline_cache() {
+  Services.prefs.setBoolPref("browser.cache.offline.enable", true);
+  Services.prefs.setBoolPref("browser.cache.offline.storage.enable", true);
   // Prepare stuff, we will work with www.example.com
   var URL = "http://www.example.com";
   var URI = makeURI(URL);
@@ -568,6 +570,8 @@ add_task(async function test_offline_cache() {
     cacheListener
   );
   await wh.promiseClosed;
+  Services.prefs.clearUserPref("browser.cache.offline.enable");
+  Services.prefs.clearUserPref("browser.cache.offline.storage.enable");
 });
 
 // Test for offline apps permission deletion
diff --git a/dom/base/nsGlobalWindowInner.cpp b/dom/base/nsGlobalWindowInner.cpp
index 75887a7c1724..f40fceaaa299 100644
--- a/dom/base/nsGlobalWindowInner.cpp
+++ b/dom/base/nsGlobalWindowInner.cpp
@@ -2982,6 +2982,12 @@ bool nsGlobalWindowInner::IsPrivilegedChromeWindow(JSContext* aCx,
              nsContentUtils::GetSystemPrincipal();
 }
 
+/* static */
+bool nsGlobalWindowInner::OfflineCacheAllowedForContext(JSContext* aCx,
+                                                        JSObject* aObj) {
+  return IsSecureContextOrObjectIsFromSecureContext(aCx, aObj);
+}
+
 /* static */
 bool nsGlobalWindowInner::IsRequestIdleCallbackEnabled(JSContext* aCx,
                                                        JSObject* aObj) {
diff --git a/dom/base/nsGlobalWindowInner.h b/dom/base/nsGlobalWindowInner.h
index 2d1b687d0ace..852cc02d8cd3 100644
--- a/dom/base/nsGlobalWindowInner.h
+++ b/dom/base/nsGlobalWindowInner.h
@@ -387,6 +387,9 @@ class nsGlobalWindowInner final : public mozilla::dom::EventTarget,
 
   static bool IsPrivilegedChromeWindow(JSContext* /* unused */, JSObject* aObj);
 
+  static bool OfflineCacheAllowedForContext(JSContext* /* unused */,
+                                            JSObject* aObj);
+
   static bool IsRequestIdleCallbackEnabled(JSContext* aCx,
                                            JSObject* /* unused */);
 
diff --git a/dom/webidl/OfflineResourceList.webidl b/dom/webidl/OfflineResourceList.webidl
index 35a017d78f12..75df4e2f296d 100644
--- a/dom/webidl/OfflineResourceList.webidl
+++ b/dom/webidl/OfflineResourceList.webidl
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-[SecureContext, Pref="browser.cache.offline.enable",
+[Pref="browser.cache.offline.enable", Func="nsGlobalWindowInner::OfflineCacheAllowedForContext",
 Exposed=Window]
 interface OfflineResourceList : EventTarget {
   /**
diff --git a/dom/webidl/Window.webidl b/dom/webidl/Window.webidl
index 92e22bc1fc58..cfe78606fea9 100644
--- a/dom/webidl/Window.webidl
+++ b/dom/webidl/Window.webidl
@@ -72,7 +72,7 @@ typedef OfflineResourceList ApplicationCache;
 #ifdef HAVE_SIDEBAR
   [Replaceable, Throws] readonly attribute External external;
 #endif
-  [Throws, SecureContext, Pref="browser.cache.offline.enable"] readonly attribute ApplicationCache applicationCache;
+  [Throws, Pref="browser.cache.offline.enable", Func="nsGlobalWindowInner::OfflineCacheAllowedForContext"] readonly attribute ApplicationCache applicationCache;
 
   // user prompts
   [Throws, NeedsSubjectPrincipal] void alert();
diff --git a/netwerk/cache/nsCacheService.cpp b/netwerk/cache/nsCacheService.cpp
index 9019c2fd2524..0949a98a10e2 100644
--- a/netwerk/cache/nsCacheService.cpp
+++ b/netwerk/cache/nsCacheService.cpp
@@ -39,7 +39,6 @@
 #include "mozilla/Services.h"
 #include "nsITimer.h"
 #include "mozIStorageService.h"
-#include "mozilla/StaticPrefs_browser.h"
 
 #include "mozilla/net/NeckoCommon.h"
 #include <algorithm>
@@ -50,6 +49,8 @@ using namespace mozilla::net;
 /******************************************************************************
  * nsCacheProfilePrefObserver
  *****************************************************************************/
+#define OFFLINE_CACHE_ENABLE_PREF "browser.cache.offline.enable"
+#define OFFLINE_CACHE_STORAGE_ENABLE_PREF "browser.cache.offline.storage.enable"
 #define OFFLINE_CACHE_DIR_PREF "browser.cache.offline.parent_directory"
 #define OFFLINE_CACHE_CAPACITY_PREF "browser.cache.offline.capacity"
 #define OFFLINE_CACHE_CAPACITY 512000
@@ -61,6 +62,14 @@ static const char* observerList[] = {
     NS_XPCOM_SHUTDOWN_OBSERVER_ID,  "last-pb-context-exited",
     "suspend_process_notification", "resume_process_notification"};
 
+static const char* prefList[] = {
+    OFFLINE_CACHE_ENABLE_PREF,
+    OFFLINE_CACHE_STORAGE_ENABLE_PREF,
+    OFFLINE_CACHE_CAPACITY_PREF,
+    OFFLINE_CACHE_DIR_PREF,
+    nullptr,
+};
+
 class nsCacheProfilePrefObserver : public nsIObserver {
   virtual ~nsCacheProfilePrefObserver() = default;
 
@@ -95,6 +104,8 @@ class nsCacheProfilePrefObserver : public nsIObserver {
     return mSanitizeOnShutdown && mClearCacheOnShutdown;
   }
 
+  void PrefChanged(const char* aPref);
+
  private:
   bool mHaveProfile;
 
@@ -142,6 +153,10 @@ nsresult nsCacheProfilePrefObserver::Install() {
   nsCOMPtr<nsIPrefBranch> branch = do_GetService(NS_PREFSERVICE_CONTRACTID);
   if (!branch) return NS_ERROR_FAILURE;
 
+  Preferences::RegisterCallbacks(
+      PREF_CHANGE_METHOD(nsCacheProfilePrefObserver::PrefChanged), prefList,
+      this);
+
   // Determine if we have a profile already
   //     Install() is called *after* the profile-after-change notification
   //     when there is only a single profile, or it is specified on the
@@ -168,6 +183,13 @@ void nsCacheProfilePrefObserver::Remove() {
       obs->RemoveObserver(this, observer);
     }
   }
+
+  // remove Pref Service observers
+  nsCOMPtr<nsIPrefBranch> prefs = do_GetService(NS_PREFSERVICE_CONTRACTID);
+  if (!prefs) return;
+  Preferences::UnregisterCallbacks(
+      PREF_CHANGE_METHOD(nsCacheProfilePrefObserver::PrefChanged), prefList,
+      this);
 }
 
 NS_IMETHODIMP
@@ -214,6 +236,40 @@ nsCacheProfilePrefObserver::Observe(nsISupports* subject, const char* topic,
   return NS_OK;
 }
 
+void nsCacheProfilePrefObserver::PrefChanged(const char* aPref) {
+  // ignore pref changes until we're done switch profiles
+  if (!mHaveProfile) return;
+  // which preference changed?
+  nsresult rv;
+  if (!strcmp(OFFLINE_CACHE_ENABLE_PREF, aPref) ||
+      !strcmp(OFFLINE_CACHE_STORAGE_ENABLE_PREF, aPref)) {
+    rv = Preferences::GetBool(OFFLINE_CACHE_ENABLE_PREF, &mOfflineCacheEnabled);
+    if (NS_FAILED(rv)) {
+      return;
+    }
+    rv = Preferences::GetBool(OFFLINE_CACHE_STORAGE_ENABLE_PREF,
+                              &mOfflineStorageCacheEnabled);
+    if (NS_FAILED(rv)) {
+      return;
+    }
+    nsCacheService::SetOfflineCacheEnabled(OfflineCacheEnabled());
+
+  } else if (!strcmp(OFFLINE_CACHE_CAPACITY_PREF, aPref)) {
+    int32_t capacity = 0;
+    rv = Preferences::GetInt(OFFLINE_CACHE_CAPACITY_PREF, &capacity);
+    if (NS_FAILED(rv)) return;
+    mOfflineCacheCapacity = std::max(0, capacity);
+    nsCacheService::SetOfflineCacheCapacity(mOfflineCacheCapacity);
+#if 0
+    } else if (!strcmp(OFFLINE_CACHE_DIR_PREF, aPref)) {
+        // XXX We probaby don't want to respond to this pref except after
+        // XXX profile changes.  Ideally, there should be some kind of user
+        // XXX notification that the pref change won't take effect until
+        // XXX the next time the profile changes (browser launch)
+#endif
+  }
+}
+
 nsresult nsCacheProfilePrefObserver::ReadPrefs(nsIPrefBranch* branch) {
   nsresult rv = NS_OK;
 
@@ -247,9 +303,13 @@ nsresult nsCacheProfilePrefObserver::ReadPrefs(nsIPrefBranch* branch) {
   }
 
   // read offline cache device prefs
-  mOfflineCacheEnabled = StaticPrefs::browser_cache_offline_enable();
+  mOfflineCacheEnabled = true;  // presume offline cache is enabled
+  (void)branch->GetBoolPref(OFFLINE_CACHE_ENABLE_PREF, &mOfflineCacheEnabled);
+
   mOfflineStorageCacheEnabled =
-      StaticPrefs::browser_cache_offline_storage_enable();
+      true;  // presume offline storage cache is enabled
+  (void)branch->GetBoolPref(OFFLINE_CACHE_STORAGE_ENABLE_PREF,
+                            &mOfflineStorageCacheEnabled);
 
   mOfflineCacheCapacity = OFFLINE_CACHE_CAPACITY;
   (void)branch->GetIntPref(OFFLINE_CACHE_CAPACITY_PREF, &mOfflineCacheCapacity);
diff --git a/testing/profiles/web-platform/user.js b/testing/profiles/web-platform/user.js
index 674af99a8199..541e936499a7 100644
--- a/testing/profiles/web-platform/user.js
+++ b/testing/profiles/web-platform/user.js
@@ -40,7 +40,3 @@ user_pref("dom.animations-api.implicit-keyframes.enabled", true);
 // sometime wpt runs test even before the document becomes visible, which would
 // delay video.play() and cause play() running in wrong order.
 user_pref("media.block-autoplay-until-in-foreground", false);
-user_pref("media.block-autoplay-until-in-foreground", false);
-// Enable AppCache globally for now whilst it's being removed in Bug 1584984
-user_pref("browser.cache.offline.storage.enable", true);
-user_pref("browser.cache.offline.enable", true);
diff --git a/toolkit/forgetaboutsite/test/unit/test_removeDataFromDomain.js b/toolkit/forgetaboutsite/test/unit/test_removeDataFromDomain.js
index c41622fbf9bf..ec10df438401 100644
--- a/toolkit/forgetaboutsite/test/unit/test_removeDataFromDomain.js
+++ b/toolkit/forgetaboutsite/test/unit/test_removeDataFromDomain.js
@@ -406,6 +406,8 @@ async function test_push_cleared() {
   const { PushService } = serviceExports;
   const userAgentID = "bd744428-f125-436a-b6d0-dd0c9845837f";
   const channelID = "0ef2ad4a-6c49-41ad-af6e-95d2425276bf";
+  Services.prefs.setBoolPref("browser.cache.offline.storage.enable", true);
+  Services.prefs.setBoolPref("browser.cache.offline.enable", true);
 
   let db = PushServiceWebSocket.newPushDB();
 
@@ -555,18 +557,10 @@ var tests = [
 
   // Storage
   test_storage_cleared,
-];
 
-// Cache
-//
-// Due to these prefs being static, setting them doesn't make a difference in time for the test
-// As we are removing AppCache in Bug 1584984 this will just be removed soon.
-if (
-  Services.prefs.getBoolPref("browser.cache.offline.enable") &&
-  Services.prefs.getBoolPref("browser.cache.offline.storage.enable")
-) {
-  tests.push(test_cache_cleared);
-}
+  // Cache
+  test_cache_cleared,
+];
 
 function run_test() {
   for (let i = 0; i < tests.length; i++) {
diff --git a/toolkit/forgetaboutsite/test/unit/xpcshell.ini b/toolkit/forgetaboutsite/test/unit/xpcshell.ini
index 5267de336e2b..4d53f0286a16 100644
--- a/toolkit/forgetaboutsite/test/unit/xpcshell.ini
+++ b/toolkit/forgetaboutsite/test/unit/xpcshell.ini
@@ -1,4 +1,5 @@
 [DEFAULT]
+prefs = [browser.cache.offline.enable = true, browser.cache.offline.storage.enable=true]
 head = head_forgetaboutsite.js ../../../../dom/push/test/xpcshell/head.js
 skip-if = toolkit == 'android'
 support-files =