diff --git a/dist/index.js b/dist/index.js
index eb5ce60..ff064d5 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -13977,6 +13977,7 @@ var encode = function encode(str, defaultEncoder, charset, kind, format) {
 
         i += 1;
         c = 0x10000 + (((c & 0x3FF) << 10) | (string.charCodeAt(i) & 0x3FF));
+        /* eslint operator-linebreak: [2, "before"] */
         out += hexTable[0xF0 | (c >> 18)]
             + hexTable[0x80 | ((c >> 12) & 0x3F)]
             + hexTable[0x80 | ((c >> 6) & 0x3F)]
@@ -17602,7 +17603,7 @@ var parseObject = function (chain, val, options, valuesParsed) {
             ) {
                 obj = [];
                 obj[index] = leaf;
-            } else {
+            } else if (cleanRoot !== '__proto__') {
                 obj[cleanRoot] = leaf;
             }
         }
@@ -34734,6 +34735,7 @@ var arrayPrefixGenerators = {
 };
 
 var isArray = Array.isArray;
+var split = String.prototype.split;
 var push = Array.prototype.push;
 var pushToArray = function (arr, valueOrArray) {
     push.apply(arr, isArray(valueOrArray) ? valueOrArray : [valueOrArray]);
@@ -34770,10 +34772,13 @@ var isNonNullishPrimitive = function isNonNullishPrimitive(v) {
         || typeof v === 'bigint';
 };
 
+var sentinel = {};
+
 var stringify = function stringify(
     object,
     prefix,
     generateArrayPrefix,
+    commaRoundTrip,
     strictNullHandling,
     skipNulls,
     encoder,
@@ -34789,8 +34794,23 @@ var stringify = function stringify(
 ) {
     var obj = object;
 
-    if (sideChannel.has(object)) {
-        throw new RangeError('Cyclic object value');
+    var tmpSc = sideChannel;
+    var step = 0;
+    var findFlag = false;
+    while ((tmpSc = tmpSc.get(sentinel)) !== void undefined && !findFlag) {
+        // Where object last appeared in the ref tree
+        var pos = tmpSc.get(object);
+        step += 1;
+        if (typeof pos !== 'undefined') {
+            if (pos === step) {
+                throw new RangeError('Cyclic object value');
+            } else {
+                findFlag = true; // Break while
+            }
+        }
+        if (typeof tmpSc.get(sentinel) === 'undefined') {
+            step = 0;
+        }
     }
 
     if (typeof filter === 'function') {
@@ -34817,6 +34837,14 @@ var stringify = function stringify(
     if (isNonNullishPrimitive(obj) || utils.isBuffer(obj)) {
         if (encoder) {
             var keyValue = encodeValuesOnly ? prefix : encoder(prefix, defaults.encoder, charset, 'key', format);
+            if (generateArrayPrefix === 'comma' && encodeValuesOnly) {
+                var valuesArray = split.call(String(obj), ',');
+                var valuesJoined = '';
+                for (var i = 0; i < valuesArray.length; ++i) {
+                    valuesJoined += (i === 0 ? '' : ',') + formatter(encoder(valuesArray[i], defaults.encoder, charset, 'value', format));
+                }
+                return [formatter(keyValue) + (commaRoundTrip && isArray(obj) && valuesArray.length === 1 ? '[]' : '') + '=' + valuesJoined];
+            }
             return [formatter(keyValue) + '=' + formatter(encoder(obj, defaults.encoder, charset, 'value', format))];
         }
         return [formatter(prefix) + '=' + formatter(String(obj))];
@@ -34831,7 +34859,7 @@ var stringify = function stringify(
     var objKeys;
     if (generateArrayPrefix === 'comma' && isArray(obj)) {
         // we need to join elements in
-        objKeys = [{ value: obj.length > 0 ? obj.join(',') || null : undefined }];
+        objKeys = [{ value: obj.length > 0 ? obj.join(',') || null : void undefined }];
     } else if (isArray(filter)) {
         objKeys = filter;
     } else {
@@ -34839,24 +34867,28 @@ var stringify = function stringify(
         objKeys = sort ? keys.sort(sort) : keys;
     }
 
-    for (var i = 0; i < objKeys.length; ++i) {
-        var key = objKeys[i];
-        var value = typeof key === 'object' && key.value !== undefined ? key.value : obj[key];
+    var adjustedPrefix = commaRoundTrip && isArray(obj) && obj.length === 1 ? prefix + '[]' : prefix;
+
+    for (var j = 0; j < objKeys.length; ++j) {
+        var key = objKeys[j];
+        var value = typeof key === 'object' && typeof key.value !== 'undefined' ? key.value : obj[key];
 
         if (skipNulls && value === null) {
             continue;
         }
 
         var keyPrefix = isArray(obj)
-            ? typeof generateArrayPrefix === 'function' ? generateArrayPrefix(prefix, key) : prefix
-            : prefix + (allowDots ? '.' + key : '[' + key + ']');
+            ? typeof generateArrayPrefix === 'function' ? generateArrayPrefix(adjustedPrefix, key) : adjustedPrefix
+            : adjustedPrefix + (allowDots ? '.' + key : '[' + key + ']');
 
-        sideChannel.set(object, true);
+        sideChannel.set(object, step);
         var valueSideChannel = getSideChannel();
+        valueSideChannel.set(sentinel, sideChannel);
         pushToArray(values, stringify(
             value,
             keyPrefix,
             generateArrayPrefix,
+            commaRoundTrip,
             strictNullHandling,
             skipNulls,
             encoder,
@@ -34880,7 +34912,7 @@ var normalizeStringifyOptions = function normalizeStringifyOptions(opts) {
         return defaults;
     }
 
-    if (opts.encoder !== null && opts.encoder !== undefined && typeof opts.encoder !== 'function') {
+    if (opts.encoder !== null && typeof opts.encoder !== 'undefined' && typeof opts.encoder !== 'function') {
         throw new TypeError('Encoder has to be a function.');
     }
 
@@ -34953,6 +34985,10 @@ module.exports = function (object, opts) {
     }
 
     var generateArrayPrefix = arrayPrefixGenerators[arrayFormat];
+    if (opts && 'commaRoundTrip' in opts && typeof opts.commaRoundTrip !== 'boolean') {
+        throw new TypeError('`commaRoundTrip` must be a boolean, or absent');
+    }
+    var commaRoundTrip = generateArrayPrefix === 'comma' && opts && opts.commaRoundTrip;
 
     if (!objKeys) {
         objKeys = Object.keys(obj);
@@ -34973,6 +35009,7 @@ module.exports = function (object, opts) {
             obj[key],
             key,
             generateArrayPrefix,
+            commaRoundTrip,
             options.strictNullHandling,
             options.skipNulls,
             options.encode ? options.encoder : null,
diff --git a/package-lock.json b/package-lock.json
index d0bd501..ab9e4f4 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -17110,9 +17110,9 @@
       }
     },
     "node_modules/qs": {
-      "version": "6.10.1",
-      "resolved": "https://registry.npmjs.org/qs/-/qs-6.10.1.tgz",
-      "integrity": "sha512-M528Hph6wsSVOBiYUnGf+K/7w0hNshs/duGsNXPUCLH5XAqjEtiPGwNONLV0tBH8NoGb0mvD5JubnUTrujKDTg==",
+      "version": "6.11.0",
+      "resolved": "https://registry.npmjs.org/qs/-/qs-6.11.0.tgz",
+      "integrity": "sha512-MvjoMCJwEarSbUYk5O+nmoSzSutSsTwF85zcHPQ9OrlFoZOYIjaqBAJIqIXjptyD5vThxGq52Xu/MaJzRkIk4Q==",
       "dependencies": {
         "side-channel": "^1.0.4"
       },
@@ -31553,9 +31553,9 @@
       "dev": true
     },
     "qs": {
-      "version": "6.10.1",
-      "resolved": "https://registry.npmjs.org/qs/-/qs-6.10.1.tgz",
-      "integrity": "sha512-M528Hph6wsSVOBiYUnGf+K/7w0hNshs/duGsNXPUCLH5XAqjEtiPGwNONLV0tBH8NoGb0mvD5JubnUTrujKDTg==",
+      "version": "6.11.0",
+      "resolved": "https://registry.npmjs.org/qs/-/qs-6.11.0.tgz",
+      "integrity": "sha512-MvjoMCJwEarSbUYk5O+nmoSzSutSsTwF85zcHPQ9OrlFoZOYIjaqBAJIqIXjptyD5vThxGq52Xu/MaJzRkIk4Q==",
       "requires": {
         "side-channel": "^1.0.4"
       }