diff --git a/src/qtism/data/storage/xml/Utils.php b/src/qtism/data/storage/xml/Utils.php
index 347b7c619..c3620ae4b 100644
--- a/src/qtism/data/storage/xml/Utils.php
+++ b/src/qtism/data/storage/xml/Utils.php
@@ -360,29 +360,65 @@ public static function valueAsString($value, $encode = true): string
         return (string)$value;
     }
 
-    public static function escapeNonCharacterRange(string $string): string
+    private static function isInCharacterRange(int $char): bool
     {
-        // Define the XML escape sequences
-        $symbolMap = [
-            '"'  => '"',
-            "'"  => ''',
-            '&'  => '&',
-            '<'  => '&lt;',
-            '>'  => '&gt;',
-            "\t" => '&#x9;',
-            "\r" => '&#xD;',
-            "\x08" => '&#xFFFD;',
-        ];
-
-        for ($char = 0xE000; $char <= 0xFFFD; $char++) {
-            $symbolMap[mb_chr($char, 'UTF-8')] = '\u{FFFD}';
-        }
-        for ($char = 0x10000; $char <= 0x10FFFF; $char++) {
-            $symbolMap[mb_chr($char, 'UTF-8')] = '\u{FFFD}';
-        }
-        $string = strtr($string, $symbolMap);
+        return $char == 0x09
+            || $char == 0x0A
+            || $char == 0x0D
+            || $char >= 0x20 && $char <= 0xDF77
+            || $char >= 0xE000 && $char <= 0xFFFD
+            || $char >= 0x10000 && $char <= 0x10FFFF;
+    }
 
-        return htmlspecialchars($string, ENT_QUOTES | ENT_XML1, 'UTF-8');
+    public static function escapeNonCharacterRange(string $value): string
+    {
+        $result = '';
+
+        $last = 0;
+        $length = strlen($value);
+        $i = 0;
+
+        while ($i < $length) {
+            $r = mb_substr(substr($value, $i), 0, 1);
+            $width = strlen($r);
+            $i += $width;
+            switch ($r) {
+            case '"':
+                $esc = '&#34;';
+                break;
+            case "'":
+                $esc = '&#39;';
+                break;
+            case '&':
+                $esc = '&amp;';
+                break;
+            case '<':
+                $esc = '&lt;';
+                break;
+            case '>':
+                $esc = '&gt;';
+                break;
+            case "\t":
+                $esc = '&#x9;';
+                break;
+            case "\n":
+                $esc = '&#xA;';
+                break;
+            case "\r":
+                $esc = '&#xD;';
+                break;
+            default:
+                if (!self::isInCharacterRange(mb_ord($r)) || (mb_ord($r) === 0xFFFD && $width === 1)) {
+                    $esc = "\u{FFFD}";
+                    break;
+                }
+
+                continue 2;
+            }
+            $result .= substr($value, $last, $i - $last - $width) . $esc;
+            $last = $i;
+        }
+        return $result . substr($value, $last);
     }
 
     /**
diff --git a/test/qtismtest/data/storage/xml/XmlUtilsTest.php b/test/qtismtest/data/storage/xml/XmlUtilsTest.php
index f79fa0bb2..917786e85 100644
--- a/test/qtismtest/data/storage/xml/XmlUtilsTest.php
+++ b/test/qtismtest/data/storage/xml/XmlUtilsTest.php
@@ -394,7 +394,7 @@ public function testFindCustomNamespaces(): void
     public function testValueAsStringReplaceSpecialSymbols(): void
     {
         $xml = ('<value>160°</value>');
-        $this->assertEquals('&amp;lt;value&amp;gt;160°&amp;#xFFFD;&amp;lt;/value&amp;gt;', Utils::valueAsString($xml));
+        $this->assertEquals('&lt;value&gt;160°�&lt;/value&gt;', Utils::valueAsString($xml));
     }
 
     public function testProcessSpecialCharsetWithoutError(): void