diff --git a/composer.json b/composer.json
index ca41778b..a2778cfb 100644
--- a/composer.json
+++ b/composer.json
@@ -25,6 +25,7 @@
     "require": {
         "php": "^5.5|^7.0",
         "ext-mbstring": "*",
+        "ext-iconv": "*",
         "ext-xml": "*",
         "ext-xmlwriter": "*"
     },
diff --git a/src/Autoloader.php b/src/Autoloader.php
index 3ed00569..7bca2ef9 100644
--- a/src/Autoloader.php
+++ b/src/Autoloader.php
@@ -38,7 +38,7 @@ class Autoloader
             spl_autoload_register('__autoload');
         }
         // Register ourselves with SPL
-        return spl_autoload_register([\PhpSpreadsheet\Autoloader::class, 'load']);
+        return spl_autoload_register([\PhpSpreadsheet\Autoloader::class, 'load'], true, true);
     }
 
     /**
diff --git a/src/PhpSpreadsheet/Calculation/TextData.php b/src/PhpSpreadsheet/Calculation/TextData.php
index 9aa7f13d..8a32a19f 100644
--- a/src/PhpSpreadsheet/Calculation/TextData.php
+++ b/src/PhpSpreadsheet/Calculation/TextData.php
@@ -28,26 +28,9 @@ class TextData
 {
     private static $invalidChars;
 
-    private static function unicodeToOrd($c)
+    private static function unicodeToOrd($character)
     {
-        if (ord($c{0}) >= 0 && ord($c{0}) <= 127) {
-            return ord($c{0});
-        } elseif (ord($c{0}) >= 192 && ord($c{0}) <= 223) {
-            return (ord($c{0}) - 192) * 64 + (ord($c{1}) - 128);
-        } elseif (ord($c{0}) >= 224 && ord($c{0}) <= 239) {
-            return (ord($c{0}) - 224) * 4096 + (ord($c{1}) - 128) * 64 + (ord($c{2}) - 128);
-        } elseif (ord($c{0}) >= 240 && ord($c{0}) <= 247) {
-            return (ord($c{0}) - 240) * 262144 + (ord($c{1}) - 128) * 4096 + (ord($c{2}) - 128) * 64 + (ord($c{3}) - 128);
-        } elseif (ord($c{0}) >= 248 && ord($c{0}) <= 251) {
-            return (ord($c{0}) - 248) * 16777216 + (ord($c{1}) - 128) * 262144 + (ord($c{2}) - 128) * 4096 + (ord($c{3}) - 128) * 64 + (ord($c{4}) - 128);
-        } elseif (ord($c{0}) >= 252 && ord($c{0}) <= 253) {
-            return (ord($c{0}) - 252) * 1073741824 + (ord($c{1}) - 128) * 16777216 + (ord($c{2}) - 128) * 262144 + (ord($c{3}) - 128) * 4096 + (ord($c{4}) - 128) * 64 + (ord($c{5}) - 128);
-        } elseif (ord($c{0}) >= 254 && ord($c{0}) <= 255) {
-            // error
-            return Functions::VALUE();
-        }
-
-        return 0;
+        return unpack('V', iconv('UTF-8', 'UCS-4LE', $character))[1];
     }
 
     /**
@@ -64,11 +47,11 @@ class TextData
             return Functions::VALUE();
         }
 
-        if (function_exists('mb_convert_encoding')) {
-            return mb_convert_encoding('&#' . intval($character) . ';', 'UTF-8', 'HTML-ENTITIES');
-        } else {
-            return chr(intval($character));
+        if (function_exists('iconv')) {
+            return iconv('UCS-4LE', 'UTF-8', pack('V', $character));
         }
+
+        return mb_convert_encoding('&#' . intval($character) . ';', 'UTF-8', 'HTML-ENTITIES');
     }
 
     /**
diff --git a/tests/data/Calculation/TextData/CHAR.php b/tests/data/Calculation/TextData/CHAR.php
index 3915d3db..c6b59428 100644
--- a/tests/data/Calculation/TextData/CHAR.php
+++ b/tests/data/Calculation/TextData/CHAR.php
@@ -1,24 +1,15 @@
 <?php
 
 return [
-    [
-        'ABC',
-        '#VALUE!',
-    ],
-    [
-        -5,
-        '#VALUE!',
-    ],
-    [
-        65,
-        'A',
-    ],
-    [
-        123,
-        '{',
-    ],
-    [
-        126,
-        '~',
-    ],
+    [ 'ABC', '#VALUE!' ],
+    [ -5, '#VALUE!' ],
+    [ 65, 'A' ],
+    [ 123, '{' ],
+    [ 126, '~' ],
+    [ 12103, "⽇" ],
+    [ 0x153, 'œ' ],
+    [ 0x192, 'ƒ' ],
+    [ 0x2105, '℅' ],
+    [ 0x2211, '∑' ],
+    [ 0x2020, '†' ],
 ];
diff --git a/tests/data/Calculation/TextData/CODE.php b/tests/data/Calculation/TextData/CODE.php
index 7cda190e..81b8a465 100644
--- a/tests/data/Calculation/TextData/CODE.php
+++ b/tests/data/Calculation/TextData/CODE.php
@@ -1,48 +1,21 @@
 <?php
 
 return [
-    [
-        null,
-        '#VALUE!',
-    ],
-    [
-        '',
-        '#VALUE!',
-    ],
-    [
-        'ABC',
-        65,
-    ],
-    [
-        123,
-        49,
-    ],
-    [
-        true,
-        84,
-    ],
-    [
-        'DEF',
-        68,
-    ],
-    [
-        'PhpSpreadsheet',
-        80,
-    ],
-    [
-        1.5,
-        49,
-    ],
-    [
-        'Mark Baker',
-        77,
-    ],
-    [
-        'mark baker',
-        109,
-    ],
-    [
-        '£125.00',
-        163,
-    ],
+    [ null, '#VALUE!' ],
+    [ '', '#VALUE!', ],
+    [ 'ABC', 65 ],
+    [ 123, 49 ],
+    [ true, 84 ],
+    [ 'DEF', 68 ],
+    [ 'PhpSpreadsheet', 80 ],
+    [ 1.5, 49 ],
+    [ 'Mark Baker', 77 ],
+    [ 'mark baker', 109 ],
+    [ '£125.00', 163 ],
+    [ "⽇", 12103],
+    [ 'œ', 0x153 ],
+    [ 'ƒ', 0x192 ],
+    [ '℅', 0x2105 ],
+    [ '∑', 0x2211 ],
+    [ '†', 0x2020 ],
 ];