diff --git a/modules/misc/news.nix b/modules/misc/news.nix
index 533b0aee3..eef1a1259 100644
--- a/modules/misc/news.nix
+++ b/modules/misc/news.nix
@@ -2259,6 +2259,16 @@ in
           A new module is available: 'programs.less'.
         '';
       }
+
+      {
+        time = "2021-11-29T15:15:59+00:00";
+        condition = hostPlatform.isDarwin;
+        message = ''
+          The option 'targets.darwin.defaults."com.apple.menuextra.battery".ShowPercent'
+          has been deprecated since it no longer works on the latest version of
+          macOS.
+        '';
+      }
     ];
   };
 }
diff --git a/modules/targets/darwin/default.nix b/modules/targets/darwin/default.nix
index d2764bd1a..9fd9dac04 100644
--- a/modules/targets/darwin/default.nix
+++ b/modules/targets/darwin/default.nix
@@ -48,6 +48,24 @@ in {
         platforms.darwin)
     ];
 
+    warnings = let
+      batteryPercentage =
+        attrByPath [ "com.apple.menuextra.battery" "ShowPercent" ] null
+        cfg.defaults;
+      webkitDevExtras = attrByPath [
+        "com.apple.Safari"
+        "com.apple.Safari.ContentPageGroupIdentifier.WebKit2DeveloperExtrasEnabled"
+      ] null cfg.defaults;
+    in optional (batteryPercentage != null) ''
+      The option 'com.apple.menuextra.battery.ShowPercent' no longer works on
+      macOS 11 and later. Instead, open System Preferences, go to "Dock &
+      Menu Bar", select "Battery", and toggle the checkbox labeled "Show
+      Percentage."
+    '' ++ optional (webkitDevExtras != null) ''
+      The option 'com.apple.Safari.com.apple.Safari.ContentPageGroupIdentifier.WebKit2DeveloperExtrasEnabled'
+      is no longer present in recent versions of Safari.
+    '';
+
     home.activation.setDarwinDefaults = hm.dag.entryAfter [ "writeBoundary" ] ''
       $VERBOSE_ECHO "Configuring macOS user defaults"
       ${concatStringsSep "\n" activationCmds}
diff --git a/modules/targets/darwin/options.nix b/modules/targets/darwin/options.nix
index f722fbfae..65ce4e011 100644
--- a/modules/targets/darwin/options.nix
+++ b/modules/targets/darwin/options.nix
@@ -98,7 +98,13 @@ in {
     "com.apple.menuextra.battery".ShowPercent = mkNullableOption {
       type = types.enum [ "YES" "NO" ];
       example = "NO";
-      description = "Whether to show battery percentage in the menu bar.";
+      description = ''
+        This option no longer works on macOS 11 and later. Instead, open System
+        Preferences, go to "Dock & Menu Bar", select "Battery", and toggle
+        the checkbox labeled "Show Percentage."
+
+        Whether to show battery percentage in the menu bar.
+      '';
     };
 
     "com.apple.Safari" = {
@@ -125,20 +131,35 @@ in {
           </warning>
         '';
       };
-      "com.apple.Safari.ContentPageGroupIdentifier.WebKit2DeveloperExtrasEnabled" =
-        mkNullableOption {
-          type = types.bool;
-          description = ''
-            Configures the web inspector.
+      "WebKitPreferences.developerExtrasEnabled" = mkNullableOption {
+        type = types.bool;
+        description = ''
+          Configures the web inspector.
 
-            <warning>
-              <para>
-                Instead of setting this option directly, set
-                <option>IncludeDevelopMenu</option> instead.
-              </para>
-            </warning>
-          '';
-        };
+          <warning>
+            <para>
+              Instead of setting this option directly, set
+              <option>IncludeDevelopMenu</option> instead.
+            </para>
+          </warning>
+        '';
+      };
+    };
+
+    "com.apple.Safari.SandboxBroker" = {
+      ShowDevelopMenu = mkNullableOption {
+        type = types.bool;
+        description = ''
+          Show the "Develop" menu in Safari's menubar.
+
+          <warning>
+            <para>
+              Instead of setting this option directly, set
+              <option>"com.apple.Safari".IncludeDevelopMenu</option> instead.
+            </para>
+          </warning>
+        '';
+      };
     };
 
     "com.googlecode.iterm2" = {
@@ -182,8 +203,11 @@ in {
   config = {
     "com.apple.Safari" = mkIf (safari.IncludeDevelopMenu != null) {
       WebKitDeveloperExtrasEnabledPreferenceKey = safari.IncludeDevelopMenu;
-      "com.apple.Safari.ContentPageGroupIdentifier.WebKit2DeveloperExtrasEnabled" =
-        safari.IncludeDevelopMenu;
+      "WebKitPreferences.developerExtrasEnabled" = safari.IncludeDevelopMenu;
     };
+    "com.apple.Safari.SandboxBroker" =
+      mkIf (safari.IncludeDevelopMenu != null) {
+        ShowDevelopMenu = safari.IncludeDevelopMenu;
+      };
   };
 }