diff --git a/composer.json b/composer.json
index 6a7455b9d..8e5924a6c 100644
--- a/composer.json
+++ b/composer.json
@@ -52,7 +52,6 @@
         "rockettheme/toolbox": "~1.5",
         "maximebf/debugbar": "~1.16",
         "league/climate": "^3.6",
-        "antoligy/dom-string-iterators": "^1.0",
         "miljar/php-exif": "^0.6",
         "composer/ca-bundle": "^1.2",
         "dragonmantank/cron-expression": "^1.2",
@@ -97,7 +96,9 @@
             "Twig\\": "system/src/Twig"
         },
         "files": [
-            "system/defines.php"
+            "system/defines.php",
+            "system/src/DOMLettersIterator.php",
+            "system/src/DOMWordsIterator.php"
         ]
     },
     "archive": {
diff --git a/composer.lock b/composer.lock
index 2bc68f592..2c4c4ea44 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,56 +4,8 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "209e1ceeafd2ef97fbf90bf4b1ec5dd4",
+    "content-hash": "1067938388862c52927c6450e8a36df0",
     "packages": [
-        {
-            "name": "antoligy/dom-string-iterators",
-            "version": "v1.0.1",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/antoligy/dom-string-iterators.git",
-                "reference": "fae88f66e1970d68c5585fc42db44f1217bf74e6"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/antoligy/dom-string-iterators/zipball/fae88f66e1970d68c5585fc42db44f1217bf74e6",
-                "reference": "fae88f66e1970d68c5585fc42db44f1217bf74e6",
-                "shasum": ""
-            },
-            "require": {
-                "php": ">=5.3.0"
-            },
-            "type": "library",
-            "autoload": {
-                "psr-4": {
-                    "": "src/"
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "CC0-1.0"
-            ],
-            "authors": [
-                {
-                    "name": "Alex Wilson",
-                    "email": "a@ax.gy"
-                },
-                {
-                    "name": "Kornel Lesinski",
-                    "email": "pornel@pornel.net"
-                },
-                {
-                    "name": "Patrick Galbraith",
-                    "email": "patrick.j.galbraith@gmail.com"
-                }
-            ],
-            "description": "Composer package for DOMWordsIterator and DOMLettersIterator",
-            "support": {
-                "issues": "https://github.com/antoligy/dom-string-iterators/issues",
-                "source": "https://github.com/antoligy/dom-string-iterators/tree/v1.0.1"
-            },
-            "time": "2018-02-03T16:01:11+00:00"
-        },
         {
             "name": "composer/ca-bundle",
             "version": "1.3.1",
diff --git a/system/src/DOMLettersIterator.php b/system/src/DOMLettersIterator.php
new file mode 100644
index 000000000..3ebe20e4f
--- /dev/null
+++ b/system/src/DOMLettersIterator.php
@@ -0,0 +1,165 @@
+<?php
+
+/**
+ * Iterates individual characters (Unicode codepoints) of DOM text and CDATA nodes
+ * while keeping track of their position in the document.
+ *
+ * Example:
+ *
+ *  $doc = new DOMDocument();
+ *  $doc->load('example.xml');
+ *  foreach(new DOMLettersIterator($doc) as $letter) echo $letter;
+ *
+ * NB: If you only need characters without their position
+ *     in the document, use DOMNode->textContent instead.
+ *
+ * @author porneL http://pornel.net
+ * @license Public Domain
+ * @url https://github.com/antoligy/dom-string-iterators
+ *
+ * @implements Iterator<int,string>
+ */
+final class DOMLettersIterator implements Iterator
+{
+    /** @var DOMElement */
+    private $start;
+    /** @var DOMElement|null */
+    private $current;
+    /** @var int */
+    private $offset = -1;
+    /** @var int|null */
+    private $key;
+    /** @var array<int,string>|null */
+    private $letters;
+
+    /**
+     * expects DOMElement or DOMDocument (see DOMDocument::load and DOMDocument::loadHTML)
+     *
+     * @param DOMNode $el
+     */
+    public function __construct(DOMNode $el)
+    {
+        if ($el instanceof DOMDocument) {
+            $el = $el->documentElement;
+        }
+
+        if (!$el instanceof DOMElement) {
+            throw new InvalidArgumentException('Invalid arguments, expected DOMElement or DOMDocument');
+        }
+
+        $this->start = $el;
+    }
+
+    /**
+     * Returns position in text as DOMText node and character offset.
+     * (it's NOT a byte offset, you must use mb_substr() or similar to use this offset properly).
+     * node may be NULL if iterator has finished.
+     *
+     * @return array
+     */
+    public function currentTextPosition(): array
+    {
+        return [$this->current, $this->offset];
+    }
+
+    /**
+     * Returns DOMElement that is currently being iterated or NULL if iterator has finished.
+     *
+     * @return DOMElement|null
+     */
+    public function currentElement(): ?DOMElement
+    {
+        return $this->current ? $this->current->parentNode : null;
+    }
+
+    // Implementation of Iterator interface
+
+    /**
+     * @return int|null
+     */
+    public function key(): ?int
+    {
+        return $this->key;
+    }
+
+    /**
+     * @return void
+     */
+    public function next(): void
+    {
+        if (null === $this->current) {
+            return;
+        }
+
+        if ($this->current->nodeType === XML_TEXT_NODE || $this->current->nodeType === XML_CDATA_SECTION_NODE) {
+            if ($this->offset === -1) {
+                preg_match_all('/./us', $this->current->textContent, $m);
+                $this->letters = $m[0];
+            }
+
+            $this->offset++;
+            $this->key++;
+            if ($this->letters && $this->offset < count($this->letters)) {
+                return;
+            }
+
+            $this->offset = -1;
+        }
+
+        while ($this->current->nodeType === XML_ELEMENT_NODE && $this->current->firstChild) {
+            $this->current = $this->current->firstChild;
+            if ($this->current->nodeType === XML_TEXT_NODE || $this->current->nodeType === XML_CDATA_SECTION_NODE) {
+                $this->next();
+                return;
+            }
+        }
+
+        while (!$this->current->nextSibling && $this->current->parentNode) {
+            $this->current = $this->current->parentNode;
+            if ($this->current === $this->start) {
+                $this->current = null;
+                return;
+            }
+        }
+
+        $this->current = $this->current->nextSibling;
+
+        $this->next();
+    }
+
+    /**
+     * Return the current element
+     * @link https://php.net/manual/en/iterator.current.php
+     *
+     * @return string|null
+     */
+    public function current(): ?string
+    {
+        return $this->letters ? $this->letters[$this->offset] : null;
+    }
+
+    /**
+     * Checks if current position is valid
+     * @link https://php.net/manual/en/iterator.valid.php
+     *
+     * @return bool
+     */
+    public function valid(): bool
+    {
+        return (bool)$this->current;
+    }
+
+    /**
+     * @return void
+     */
+    public function rewind(): void
+    {
+        $this->current = $this->start;
+        $this->offset = -1;
+        $this->key = -1;
+        $this->letters = [];
+
+        $this->next();
+    }
+}
+
diff --git a/system/src/DOMWordsIterator.php b/system/src/DOMWordsIterator.php
new file mode 100644
index 000000000..31ca90fe9
--- /dev/null
+++ b/system/src/DOMWordsIterator.php
@@ -0,0 +1,158 @@
+<?php
+
+/**
+ * Iterates individual words of DOM text and CDATA nodes
+ * while keeping track of their position in the document.
+ *
+ * Example:
+ *
+ *  $doc = new DOMDocument();
+ *  $doc->load('example.xml');
+ *  foreach(new DOMWordsIterator($doc) as $word) echo $word;
+ *
+ * @author pjgalbraith http://www.pjgalbraith.com
+ * @author porneL http://pornel.net (based on DOMLettersIterator available at http://pornel.net/source/domlettersiterator.php)
+ * @license Public Domain
+ * @url https://github.com/antoligy/dom-string-iterators
+ *
+ * @implements Iterator<int,string>
+ */
+
+final class DOMWordsIterator implements Iterator
+{
+    /** @var DOMElement */
+    private $start;
+    /** @var DOMElement|null */
+    private $current;
+    /** @var int */
+    private $offset = -1;
+    /** @var int|null */
+    private $key;
+    /** @var array<int,string>|null */
+    private $words;
+
+    /**
+     * expects DOMElement or DOMDocument (see DOMDocument::load and DOMDocument::loadHTML)
+     *
+     * @param DOMNode $el
+     */
+    public function __construct(DOMNode $el)
+    {
+        if ($el instanceof DOMDocument) {
+            $el = $el->documentElement;
+        }
+
+        if (!$el instanceof DOMElement) {
+            throw new InvalidArgumentException('Invalid arguments, expected DOMElement or DOMDocument');
+        }
+
+        $this->start = $el;
+    }
+
+    /**
+     * Returns position in text as DOMText node and character offset.
+     * (it's NOT a byte offset, you must use mb_substr() or similar to use this offset properly).
+     * node may be NULL if iterator has finished.
+     *
+     * @return array
+     */
+    public function currentWordPosition(): array
+    {
+        return [$this->current, $this->offset, $this->words];
+    }
+
+    /**
+     * Returns DOMElement that is currently being iterated or NULL if iterator has finished.
+     *
+     * @return DOMElement|null
+     */
+    public function currentElement(): ?DOMElement
+    {
+        return $this->current ? $this->current->parentNode : null;
+    }
+
+    // Implementation of Iterator interface
+
+    /**
+     * Return the key of the current element
+     * @link https://php.net/manual/en/iterator.key.php
+     * @return int|null
+     */
+    public function key(): ?int
+    {
+        return $this->key;
+    }
+
+    /**
+     * @return void
+     */
+    public function next(): void
+    {
+        if (null === $this->current) {
+            return;
+        }
+
+        if ($this->current->nodeType === XML_TEXT_NODE || $this->current->nodeType === XML_CDATA_SECTION_NODE) {
+            if ($this->offset === -1) {
+                $this->words = preg_split("/[\n\r\t ]+/u", $this->current->textContent, -1, PREG_SPLIT_NO_EMPTY) ?: [];
+            }
+            $this->offset++;
+
+            if ($this->words && $this->offset < count($this->words)) {
+                $this->key++;
+                return;
+            }
+            $this->offset = -1;
+        }
+
+        while ($this->current->nodeType === XML_ELEMENT_NODE && $this->current->firstChild) {
+            $this->current = $this->current->firstChild;
+            if ($this->current->nodeType === XML_TEXT_NODE || $this->current->nodeType === XML_CDATA_SECTION_NODE) {
+                $this->next();
+                return;
+            }
+        }
+
+        while (!$this->current->nextSibling && $this->current->parentNode) {
+            $this->current = $this->current->parentNode;
+            if ($this->current === $this->start) {
+                $this->current = null;
+                return;
+            }
+        }
+
+        $this->current = $this->current->nextSibling;
+
+        $this->next();
+    }
+
+    /**
+     * Return the current element
+     * @link https://php.net/manual/en/iterator.current.php
+     * @return string|null
+     */
+    public function current(): ?string
+    {
+        return $this->words ? $this->words[$this->offset] : null;
+    }
+
+    /**
+     * Checks if current position is valid
+     * @link https://php.net/manual/en/iterator.valid.php
+     * @return bool
+     */
+    public function valid(): bool
+    {
+        return (bool)$this->current;
+    }
+
+    public function rewind(): void
+    {
+        $this->current = $this->start;
+        $this->offset = -1;
+        $this->key = -1;
+        $this->words = [];
+
+        $this->next();
+    }
+}