diff --git a/pkg/dohdec/lib/dnsUtils.js b/pkg/dohdec/lib/dnsUtils.js
index 9de8ba9..baac6db 100644
--- a/pkg/dohdec/lib/dnsUtils.js
+++ b/pkg/dohdec/lib/dnsUtils.js
@@ -15,10 +15,14 @@ const PAD_SIZE = 128;
  * @property {string} [rrtype] The Resource Record type to retrive.
  * @property {number} [id] The 2-byte unsigned integer for the request.
  *   For DOH, should be 0 or undefined.
- * @property {boolean} [json] Force JSON lookups for DOH.  Ignored for DOT.
+ * @property {boolean} [decode=true] Decode the response, either into JSON
+ *   or an object representing the DNS format result.
  * @property {boolean} [stream=false] Encode for streaming, with the packet
  *   prefixed by a 2-byte big-endian integer of the number of bytes in the
  *   packet.
+ * @property {boolean} [dnssec=false] Request DNSSec records.  Currently
+ *   requires `json: false`.
+ * @property {boolean} [dnssecCheckingDisabled=false] Disable DNSSEC
  */
 
 // Extracted from node source.
@@ -236,7 +240,7 @@ export class DNSutils extends EventEmitter {
    */
   static normalizeArgs(name, opts, defaults) {
     /** @type {LookupOptions} */
-    let nopts = {};
+    let nopts = Object.create(null);
     if (name != null) {
       switch (typeof name) {
         case 'object':
diff --git a/pkg/dohdec/lib/doh.js b/pkg/dohdec/lib/doh.js
index 62226de..f98a1d1 100644
--- a/pkg/dohdec/lib/doh.js
+++ b/pkg/dohdec/lib/doh.js
@@ -18,20 +18,17 @@ const USER_AGENT = `${pkg.name} v${pkg.version}`;
 /**
  * Options for doing DOH lookups.
  *
- * @typedef {object} DOH_LookupOptions
- * @property {string} [name] The DNS name to look up.
- * @property {string} [rrtype='A'] The Resource Record type
- *   to retrive.
- * @property {boolean} [json=true] Retrieve a JSON response.  If false,
- *   retrieve using DNS format.
- * @property {boolean} [decode=true] Decode the response, either into JSON
- *   or an object representing the DNS format result.
+ * @typedef {object} DOH_SpecificLookupOptions
  * @property {boolean} [preferPost=true] For DNS format requests, should
  *   the HTTP POST verb be used?  If false, uses GET.
- * @property {boolean} [dnssec=false] Request DNSSec records.  Currently
- *   requires `json: false`.
  * @property {string} [url=CLOUDFLARE_API] What DoH endpoint should be
  *   used?
+ * @property {boolean} [json=true] Force JSON lookups for DOH.
+ */
+
+/**
+ * @typedef {DOH_SpecificLookupOptions &
+ *   import('./dnsUtils.js').LookupOptions} DOH_LookupOptions
  */
 
 /**
@@ -200,13 +197,15 @@ export class DNSoverHTTPS extends DNSutils {
    * @returns {Promise<Buffer|string|object>} DNS result.
    */
   lookup(name, opts = {}) {
-    const nopts = DNSutils.normalizeArgs(name, opts, {
-      rrtype: 'A',
-      json: true,
-      decode: true,
-      dnssec: false,
-      dnssecCheckingDisabled: false,
-    });
+    const nopts = /** @type {Required<DOH_LookupOptions>} */ (
+      DNSutils.normalizeArgs(name, opts, {
+        rrtype: 'A',
+        json: true,
+        decode: true,
+        dnssec: false,
+        dnssecCheckingDisabled: false,
+      })
+    );
     this.verbose(1, 'DNSoverHTTPS.lookup options:', nopts);
 
     return nopts.json ? this.getJSON(nopts) : this.getDNS(nopts);
diff --git a/pkg/dohdec/lib/dot.js b/pkg/dohdec/lib/dot.js
index 8fabfee..69e214b 100644
--- a/pkg/dohdec/lib/dot.js
+++ b/pkg/dohdec/lib/dot.js
@@ -15,15 +15,7 @@ const DEFAULT_SERVER = '1.1.1.1';
 /**
  * Options for doing DOT lookups.
  *
- * @typedef {object} DOT_LookupOptions
- * @property {string} [name] The DNS name to look up.
- * @property {string} [rrtype='A'] The Resource Record type
- *   to retrive.
- * @property {number} [id] 2-byte ID for the DNS packet.  Defaults to random.
- * @property {boolean} [decode=true] Decode the response, either into JSON
- *   or an object representing the DNS format result.
- * @property {boolean} [dnssec=false] Request DNSSec records.  Currently
- *   requires `json: false`.
+ * @typedef {import('./dnsUtils.js').LookupOptions} DOT_LookupOptions
  */
 
 /**