diff --git a/lib/utils/strings.js b/lib/utils/strings.js
index c8f097cd..d0e07980 100644
--- a/lib/utils/strings.js
+++ b/lib/utils/strings.js
@@ -15,12 +15,16 @@ try { String.fromCharCode.apply(null, new Uint8Array(1)); } catch (__) { STR_APP
 // Table with utf8 lengths (calculated by first byte of sequence)
 // Note, that 5 & 6-byte values and some 4-byte values can not be represented in JS,
 // because max possible codepoint is 0x10ffff
-const _utf8len = new Uint8Array(256);
-for (let q = 0; q < 256; q++) {
-  _utf8len[q] = (q >= 252 ? 6 : q >= 248 ? 5 : q >= 240 ? 4 : q >= 224 ? 3 : q >= 192 ? 2 : 1);
+let _utf8len = null;
+function maybeInitializeUtf8LenBuffer() {
+  if (_utf8len === null) {
+    _utf8len = new Uint8Array(256);
+    for (let q = 0; q < 256; q++) {
+      _utf8len[q] = (q >= 252 ? 6 : q >= 248 ? 5 : q >= 240 ? 4 : q >= 224 ? 3 : q >= 192 ? 2 : 1);
+    }
+    _utf8len[254] = _utf8len[254] = 1; // Invalid sequence start
+  }
 }
-_utf8len[254] = _utf8len[254] = 1; // Invalid sequence start
-
 
 // convert string to array (typed, when possible)
 module.exports.string2buf = (str) => {
@@ -113,6 +117,7 @@ module.exports.buf2string = (buf, max) => {
   // NB: by unknown reasons, Array is significantly faster for
   //     String.fromCharCode.apply than Uint16Array.
   const utf16buf = new Array(len * 2);
+  maybeInitializeUtf8LenBuffer();
 
   for (out = 0, i = 0; i < len;) {
     let c = buf[i++];
@@ -169,6 +174,8 @@ module.exports.utf8border = (buf, max) => {
   // If we came to start of buffer - that means buffer is too small,
   // return max too.
   if (pos === 0) { return max; }
+  
+  maybeInitializeUtf8LenBuffer();
 
   return (pos + _utf8len[buf[pos]] > max) ? pos : max;
 };