--- a/electron.old.d.ts
+++ b/electron.new.d.ts
@@ -14739,13 +14739,13 @@ declare namespace Electron {
      */
     enableBuiltInResolver?: boolean;
     /**
-     * Can be "off", "automatic" or "secure". Configures the DNS-over-HTTP mode. When
-     * "off", no DoH lookups will be performed. When "automatic", DoH lookups will be
+     * Can be 'off', 'automatic' or 'secure'. Configures the DNS-over-HTTP mode. When
+     * 'off', no DoH lookups will be performed. When 'automatic', DoH lookups will be
      * performed first if DoH is available, and insecure DNS lookups will be performed
-     * as a fallback. When "secure", only DoH lookups will be performed. Defaults to
-     * "automatic".
+     * as a fallback. When 'secure', only DoH lookups will be performed. Defaults to
+     * 'automatic'.
      */
-    secureDnsMode?: string;
+    secureDnsMode?: ('off' | 'automatic' | 'secure');
     /**
      * A list of DNS-over-HTTP server templates. See RFC8484 § 3 for details on the
      * template format. Most servers support the POST method; the template for such
@@ -15619,10 +15619,10 @@ declare namespace Electron {
 
   interface InsertCSSOptions {
     /**
-     * Can be either 'user' or 'author'. Sets the cascade origin of the inserted
-     * stylesheet. Default is 'author'.
+     * Can be 'user' or 'author'. Sets the cascade origin of the inserted stylesheet.
+     * Default is 'author'.
      */
-    cssOrigin?: string;
+    cssOrigin?: ('user' | 'author');
   }
 
   interface IpcMessageEvent extends DOMEvent {