diff --git a/composer.json b/composer.json
index acc00b0..5398c21 100644
--- a/composer.json
+++ b/composer.json
@@ -16,11 +16,15 @@
     ],
     "require": {
         "php": ">= 7.2",
-        "nette/utils": "^3.2.5"
+        "ext-json": "*"
     },
     "require-dev": {
-        "phpstan/phpstan": "^0.12.98",
-        "nette/tester": "^2.4"
+        "nette/tester": "^2.4",
+        "nette/utils": "^3.2.5",
+        "phpstan/phpstan": "^0.12.98"
+    },
+    "suggest": {
+        "nette/utils": "Allows to safe escape HTML with markup: https://doc.nette.org/en/utils/html-elements"
     },
     "autoload": {
         "psr-4": {
@@ -30,5 +34,8 @@
     "scripts": {
         "phpstan": "phpstan analyze src -c phpstan.neon --level 7",
         "tester": "tester tests"
+    },
+    "config": {
+        "sort-packages": true
     }
 }
diff --git a/src/Escape.php b/src/Escape.php
index dc3d322..cf8e403 100644
--- a/src/Escape.php
+++ b/src/Escape.php
@@ -7,7 +7,7 @@
 
 use Nette\HtmlStringable;
 use Nette\Utils\IHtmlString;
-use Nette\Utils\Json;
+use RuntimeException;
 
 /**
  * Escape funxtions. Uses UTF-8 only.
@@ -99,7 +99,11 @@ public static function js($data): string
             $data = (string)$data;
         }
 
-        $json = Json::encode($data);
+        $json = json_encode($data, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_PRESERVE_ZERO_FRACTION);
+
+        if ($json === false) {
+            throw new RuntimeException("JSON encode failed: " . json_last_error_msg(), json_last_error());
+        }
 
         return str_replace([']]>', '<!', '</'], [']]\u003E', '\u003C!', '<\/'], $json);
     }
diff --git a/src/EscapeCss.php b/src/EscapeCss.php
index 8d13635..8c4c6b1 100644
--- a/src/EscapeCss.php
+++ b/src/EscapeCss.php
@@ -5,8 +5,6 @@
 
 namespace JakubBoucek\Escape;
 
-use Nette\Utils\Strings;
-
 class EscapeCss
 {
     /**
@@ -43,12 +41,12 @@ class EscapeCss
      */
     public static function color(string $color): string
     {
-        $valid = (bool)Strings::match(
-            $color,
-            '/^\s*(?:[-a-zA-Z]+|#[\da-fA-F]{3,8}|(?:rgba?|hsla?|lch|lab)\([\d,.%\\/ ]+\))\s*$/D'
+        $result = preg_match(
+            '/^\s*(?:[-a-zA-Z]+|#[\da-fA-F]{3,8}|(?:rgba?|hsla?|lch|lab)\([\d,.%\\/ ]+\))\s*$/D',
+            $color
         );
 
-        if ($valid === false) {
+        if ($result !== 1) {
             return '';
         }