diff --git a/docs/tests/hnset-benchmark.html b/docs/tests/hnset-benchmark.html
index eda502ae8..cca2425e6 100644
--- a/docs/tests/hnset-benchmark.html
+++ b/docs/tests/hnset-benchmark.html
@@ -17,7 +17,7 @@
 
 <script src="https://rawcdn.githack.com/gorhill/uBlock/e83ffde5af29bd44ae529c5a60e2506970e7af34/src/js/hntrie.js"></script>
 <script src="https://raw.githack.com/gorhill/uBlock/master/src/js/hntrie.js"></script>
-<!-- script src="../../src/js/hntrie.js"></script> -->
+<!-- <script src="../../src/js/hntrie.js"></script> -->
 <script src="hostname-pool.js"></script>
 
 <script src="https://cdn.jsdelivr.net/lodash/4.17.2/lodash.min.js"></script>
@@ -289,11 +289,11 @@ function initBenchmarks() {
         const bms = new Benchmark.Suite();
         const needles = [];
 
-        let setDicts = [];
-        let regexDicts = [];
-        let oldTrieDicts = []
-        let newTrieDicts = []
-        let results = [];
+        let setDicts;
+        let regexDicts;
+        let oldTrieDicts;
+        let newTrieDicts;
+        let results;
 
         const lookupDict = function(dicts, fn) {
             for ( let i = 0; i < needles.length; i++ ) {
@@ -325,6 +325,7 @@ function initBenchmarks() {
                 regexDicts = [];
                 oldTrieDicts = []
                 newTrieDicts = []
+                results = [];
                 hnTrieManager.reset();
                 for ( const domainOpt of domainOpts ) {
                     setDicts.push(setBasedDictCreate(domainOpt));
@@ -339,7 +340,11 @@ function initBenchmarks() {
             .on('cycle', function(event) {
                 stdout(gWhich, String(event.target) + '\n');
                 })
-            .on('complete', exitBenchmark);
+            .on('complete', ( ) => {
+                setDicts = regexDicts = oldTrieDicts = newTrieDicts = results = undefined;
+                hnTrieManager.reset();
+                exitBenchmark();
+                });
 
         if ( hnTrieManager.matchesWASM !== null ) {
             bms.add('  -     Trie-based WASM', function() {
diff --git a/docs/tests/hntrie-test.html b/docs/tests/hntrie-test.html
index e4c7114c6..39d99dfae 100644
--- a/docs/tests/hntrie-test.html
+++ b/docs/tests/hntrie-test.html
@@ -10,7 +10,7 @@
 <div id="stdout"></div>
 <script src="https://rawcdn.githack.com/gorhill/uBlock/e83ffde5af29bd44ae529c5a60e2506970e7af34/src/js/hntrie.js"></script>
 <script src="https://raw.githack.com/gorhill/uBlock/master/src/js/hntrie.js"></script>
-<!-- script src="../../src/js/hntrie.js"></script> -->
+<!-- <script src="../../src/js/hntrie.js"></script> -->
 <script src="hostname-pool.js"></script>
 <script>
 const createRandomLabel = function() {
diff --git a/src/js/hntrie.js b/src/js/hntrie.js
index ef66e032c..381fcb451 100644
--- a/src/js/hntrie.js
+++ b/src/js/hntrie.js
@@ -65,7 +65,7 @@ const hnTrieManager = {
     reset: function() {
         if ( this.wasmMemory === null && this.trie.byteLength > 65536 ) {
             this.trie = new Uint8Array(65536);
-            this.trie32 = new Uint32Array(this.trie.buffer);
+            this.trie32 = null;
         } else {
             this.trie.fill(0);
         }
@@ -88,6 +88,7 @@ const hnTrieManager = {
         if ( needle !== this.needle ) {
             const buf = this.trie;
             let i = needle.length;
+            if ( i > 255 ) { i = 255; }
             buf[255] = i;
             while ( i-- ) {
                 buf[i] = needle.charCodeAt(i);
@@ -167,12 +168,13 @@ const hnTrieManager = {
     */
 
     add: function(hn) {
+        let ichar = hn.length - 1;
+        if ( ichar === -1 ) { return; }
         // 256 * 3 + 3 = 771
         if ( this.treesz + 771 >= this.tree.length ) {
             this.growTree();
         }
-        let ichar = hn.length - 1;
-        if ( ichar === -1 ) { return; }
+        if ( ichar > 254 ) { ichar = 254; }
         let c = hn.charCodeAt(ichar),
             i = 0, inext;
         for (;;) {
@@ -313,8 +315,8 @@ const hnTrieManager = {
           byte 7: number of extra characters
           Offset & count values are little-endian.
 
-          3 + 3 + 1 + 1 = 8 bytes for one character, otherwise
-          3 + 3 + 1 + 1 + n = 8 + n bytes for one + n character(s)
+          4 + 4 + 1 + 1 = 10 bytes for one character, otherwise
+          4 + 4 + 1 + 1 + n = 10 + n bytes for one + n character(s)
     */
 
     finish: function() {
@@ -410,7 +412,7 @@ const hnTrieManager = {
                 } else {
                     this.tree = null;
                 }
-            }, 30000);
+            }, 10000);
         }
     },