diff --git a/composer.json b/composer.json
index 15f9989f532..6bb1a84571e 100644
--- a/composer.json
+++ b/composer.json
@@ -17,7 +17,7 @@
     "ampproject/amp-toolbox": "0.11.6",
     "cweagans/composer-patches": "^1.0",
     "fasterimage/fasterimage": "1.5.0",
-    "sabberworm/php-css-parser": "8.5.1"
+    "sabberworm/php-css-parser": "8.8.0"
   },
   "require-dev": {
     "automattic/vipwpcs": "^3.0",
diff --git a/composer.lock b/composer.lock
index 5f9854ebb00..e08050dd746 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "38508cfd56b1c92381dea8329cf7239a",
+    "content-hash": "b55665803a6c11bec11c744cc5e88968",
     "packages": [
         {
             "name": "ampproject/amp-toolbox",
@@ -189,24 +189,24 @@
         },
         {
             "name": "sabberworm/php-css-parser",
-            "version": "v8.5.1",
+            "version": "v8.8.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/MyIntervals/PHP-CSS-Parser.git",
-                "reference": "4a3d572b0f8b28bb6fd016ae8bbfc445facef152"
+                "reference": "3de493bdddfd1f051249af725c7e0d2c38fed740"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/MyIntervals/PHP-CSS-Parser/zipball/4a3d572b0f8b28bb6fd016ae8bbfc445facef152",
-                "reference": "4a3d572b0f8b28bb6fd016ae8bbfc445facef152",
+                "url": "https://api.github.com/repos/MyIntervals/PHP-CSS-Parser/zipball/3de493bdddfd1f051249af725c7e0d2c38fed740",
+                "reference": "3de493bdddfd1f051249af725c7e0d2c38fed740",
                 "shasum": ""
             },
             "require": {
                 "ext-iconv": "*",
-                "php": ">=5.6.20"
+                "php": "^5.6.20 || ^7.0.0 || ~8.0.0 || ~8.1.0 || ~8.2.0 || ~8.3.0 || ~8.4.0"
             },
             "require-dev": {
-                "phpunit/phpunit": "^5.7.27"
+                "phpunit/phpunit": "5.7.27 || 6.5.14 || 7.5.20 || 8.5.41"
             },
             "suggest": {
                 "ext-mbstring": "for parsing UTF-8 CSS"
@@ -248,9 +248,9 @@
             ],
             "support": {
                 "issues": "https://github.com/MyIntervals/PHP-CSS-Parser/issues",
-                "source": "https://github.com/MyIntervals/PHP-CSS-Parser/tree/v8.5.1"
+                "source": "https://github.com/MyIntervals/PHP-CSS-Parser/tree/v8.8.0"
             },
-            "time": "2024-02-15T16:41:13+00:00"
+            "time": "2025-03-23T17:59:05+00:00"
         },
         {
             "name": "willwashburn/stream",