diff --git a/CHANGELOG.md b/CHANGELOG.md
index 936329a6..a8b91e8c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ For a full diff see [`2.42.0...main`][2.42.0...main].
 ### Changed
 
 - Updated `composer/composer` ([#1292]), by [@localheinz]
+- Updated `schema.json` ([#1312]), by [@ergebnis-bot]
 
 ## [`2.42.0`][2.42.0]
 
@@ -1227,6 +1228,7 @@ For a full diff see [`81bc3a8...0.1.0`][81bc3a8...0.1.0].
 [#1278]: https://github.com/ergebnis/composer-normalize/pull/1278
 [#1279]: https://github.com/ergebnis/composer-normalize/pull/1279
 [#1292]: https://github.com/ergebnis/composer-normalize/pull/1292
+[#1312]: https://github.com/ergebnis/composer-normalize/pull/1312
 
 [@core23]: https://github.com/core23
 [@dependabot]: https://github.com/dependabot
diff --git a/resource/schema.json b/resource/schema.json
index 21173ba9..b23588e8 100644
--- a/resource/schema.json
+++ b/resource/schema.json
@@ -342,6 +342,54 @@
                 }
             }
         },
+        "php-ext": {
+            "type": "object",
+            "description": "Settings for PHP extension packages.",
+            "properties": {
+                "extension-name": {
+                    "type": "string",
+                    "description": "If specified, this will be used as the name of the extension, where needed by tooling. If this is not specified, the extension name will be derived from the Composer package name (e.g. `vendor/name` would become `ext-name`). The extension name may be specified with or without the `ext-` prefix, and tools that use this must normalise this appropriately.",
+                    "example": "ext-xdebug"
+                },
+                "priority": {
+                    "type": "integer",
+                    "description": "This is used to add a prefix to the INI file, e.g. `90-xdebug.ini` which affects the loading order. The priority is a number in the range 10-99 inclusive, with 10 being the highest priority (i.e. will be processed first), and 99 being the lowest priority (i.e. will be processed last). There are two digits so that the files sort correctly on any platform, whether the sorting is natural or not.",
+                    "minimum": 10,
+                    "maximum": 99,
+                    "example": 80,
+                    "default": 80
+                },
+                "support-zts": {
+                    "type": "boolean",
+                    "description": "Does this package support Zend Thread Safety",
+                    "example": false,
+                    "default": true
+                },
+                "configure-options": {
+                    "type": "array",
+                    "description": "These configure options make up the flags that can be passed to ./configure when installing the extension.",
+                    "items": {
+                        "type": "object",
+                        "required": [
+                            "name"
+                        ],
+                        "properties": {
+                            "name": {
+                                "type": "string",
+                                "description": "The name of the flag, this would typically be prefixed with `--`, for example, the value 'the-flag' would be passed as `./configure --the-flag`.",
+                                "example": "without-xdebug-compression",
+                                "pattern": "^[a-zA-Z0-9][a-zA-Z0-9-_]*$"
+                            },
+                            "description": {
+                                "type": "string",
+                                "description": "The description of what the flag does or means.",
+                                "example": "Disable compression through zlib"
+                            }
+                        }
+                    }
+                }
+            }
+        },
         "config": {
             "type": "object",
             "description": "Composer options.",