diff --git a/composer.json b/composer.json
index abc84b668e8..2671c0d4ef3 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
     "ext-json": "*",
     "ext-libxml": "*",
     "ext-spl": "*",
-    "ampproject/amp-toolbox": "dev-main",
+    "ampproject/amp-toolbox": "0.11.4",
     "cweagans/composer-patches": "^1.0",
     "fasterimage/fasterimage": "1.5.0",
     "sabberworm/php-css-parser": "dev-master#cc791ad"
diff --git a/composer.lock b/composer.lock
index 671de35146e..378ce091b75 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,11 +4,11 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "06d098e8f871b8cc6e0e676e8ee4c226",
+    "content-hash": "fce7eaa51eae83b212188c83fb02faa9",
     "packages": [
         {
             "name": "ampproject/amp-toolbox",
-            "version": "dev-main",
+            "version": "0.11.4",
             "source": {
                 "type": "git",
                 "url": "https://github.com/ampproject/amp-toolbox-php.git",
@@ -48,7 +48,6 @@
                 "mck89/peast": "Needed to minify the AMP script.",
                 "nette/php-generator": "Needed to generate the validator spec PHP classes and interfaces."
             },
-            "default-branch": true,
             "bin": [
                 "bin/amp"
             ],
@@ -77,7 +76,7 @@
             "description": "A collection of AMP tools making it easier to publish and host AMP pages with PHP.",
             "support": {
                 "issues": "https://github.com/ampproject/amp-toolbox-php/issues",
-                "source": "https://github.com/ampproject/amp-toolbox-php/tree/main"
+                "source": "https://github.com/ampproject/amp-toolbox-php/tree/0.11.4"
             },
             "time": "2023-10-24T22:47:58+00:00"
         },
@@ -8138,7 +8137,6 @@
     "aliases": [],
     "minimum-stability": "dev",
     "stability-flags": {
-        "ampproject/amp-toolbox": 20,
         "sabberworm/php-css-parser": 20,
         "roave/security-advisories": 20
     },