diff --git a/.composer-require-checker.json b/.composer-require-checker.json
new file mode 100644
index 0000000000..dc85dc0e97
--- /dev/null
+++ b/.composer-require-checker.json
@@ -0,0 +1,90 @@
+{
+  "symbol-whitelist": [
+    "array",
+    "Composer\\Autoload\\ClassLoader",
+    "false",
+    "null",
+    "parent",
+    "pcntl_fork",
+    "pcntl_waitpid",
+    "pcntl_wexitstatus",
+    "PHP_CODESNIFFER_CBF",
+    "PHP_CODESNIFFER_VERBOSITY",
+    "PHP_CodeSniffer\\Tests\\Standards\\AbstractSniffUnitTest",
+    "posix_isatty",
+    "self",
+    "T_ANON_CLASS",
+    "T_ASPERAND",
+    "T_ATTRIBUTE_END",
+    "T_BACKTICK",
+    "T_BINARY_CAST",
+    "T_BITWISE_AND",
+    "T_BITWISE_NOT",
+    "T_BITWISE_OR",
+    "T_BITWISE_XOR",
+    "T_BOOLEAN_NOT",
+    "T_CLOSE_CURLY_BRACKET",
+    "T_CLOSE_PARENTHESIS",
+    "T_CLOSE_SHORT_ARRAY",
+    "T_CLOSE_SQUARE_BRACKET",
+    "T_CLOSE_USE_GROUP",
+    "T_CLOSURE",
+    "T_COLON",
+    "T_COMMA",
+    "T_DIVIDE",
+    "T_DOC_COMMENT_CLOSE_TAG",
+    "T_DOC_COMMENT_OPEN_TAG",
+    "T_DOC_COMMENT_STAR",
+    "T_DOC_COMMENT_STRING",
+    "T_DOC_COMMENT_TAG",
+    "T_DOC_COMMENT_WHITESPACE",
+    "T_DOLLAR",
+    "T_DOUBLE_QUOTED_STRING",
+    "T_END_NOWDOC",
+    "T_ENUM_CASE",
+    "T_EQUAL",
+    "T_FALSE",
+    "T_FN_ARROW",
+    "T_GOTO_LABEL",
+    "T_GREATER_THAN",
+    "T_HEREDOC",
+    "T_INLINE_ELSE",
+    "T_INLINE_THEN",
+    "T_LESS_THAN",
+    "T_MATCH_ARROW",
+    "T_MATCH_DEFAULT",
+    "T_MINUS",
+    "T_MODULUS",
+    "T_MULTIPLY",
+    "T_NONE",
+    "T_NOWDOC",
+    "T_NULL",
+    "T_NULLABLE",
+    "T_OBJECT",
+    "T_OPEN_CURLY_BRACKET",
+    "T_OPEN_PARENTHESIS",
+    "T_OPEN_SHORT_ARRAY",
+    "T_OPEN_SQUARE_BRACKET",
+    "T_OPEN_USE_GROUP",
+    "T_PARAM_NAME",
+    "T_PARENT",
+    "T_PHPCS_DISABLE",
+    "T_PHPCS_ENABLE",
+    "T_PHPCS_IGNORE_FILE",
+    "T_PHPCS_IGNORE",
+    "T_PHPCS_SET",
+    "T_PLUS",
+    "T_PROPERTY",
+    "T_PROTOTYPE",
+    "T_SELF",
+    "T_SEMICOLON",
+    "T_START_NOWDOC",
+    "T_STRING_CONCAT",
+    "T_THIS",
+    "T_TRUE",
+    "T_TYPE_INTERSECTION",
+    "T_TYPE_UNION",
+    "T_ZSR_EQUAL",
+    "true"
+  ]
+}
diff --git a/.gitattributes b/.gitattributes
index 3e7371b7a0..2286c3eda0 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,3 +1,4 @@
+.composer-require-checker.json export-ignore
 .cspell.json export-ignore
 .gitattributes export-ignore
 .github/ export-ignore
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 480b5d14b2..d19f5ec52d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -142,10 +142,6 @@ jobs:
         if: ${{ matrix.custom_ini == false && matrix.php == '7.4' }}
         run: cs2pr ./phpcs-report.xml
 
-      - name: 'Composer: validate config'
-        if: ${{ matrix.custom_ini  == false }}
-        run: composer validate --no-check-all --strict
-
       - name: Download the PHPCS phar
         uses: actions/download-artifact@v3
         with:
diff --git a/.github/workflows/validate.yml b/.github/workflows/validate.yml
index 48f6209d7c..94894a3c1a 100644
--- a/.github/workflows/validate.yml
+++ b/.github/workflows/validate.yml
@@ -57,3 +57,20 @@ jobs:
           diff -B ./src/Standards/PSR12/ruleset.xml <(xmllint --format "./src/Standards/PSR12/ruleset.xml")
           diff -B ./src/Standards/Squiz/ruleset.xml <(xmllint --format "./src/Standards/Squiz/ruleset.xml")
           diff -B ./src/Standards/Zend/ruleset.xml <(xmllint --format "./src/Standards/Zend/ruleset.xml")
+
+  check-composer:
+    name: Check composer.json
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v3
+
+      - name: 'Composer: validate config'
+        run: composer --no-interaction validate --no-check-all --strict
+
+      - name: Install Composer dependencies
+        uses: "ramsey/composer-install@v2"
+
+      - name: 'Composer require checker'
+        run: vendor/bin/composer-require-checker check --config-file=.composer-require-checker.json
diff --git a/composer.json b/composer.json
index 0ada4e5535..25cd4cd6bf 100644
--- a/composer.json
+++ b/composer.json
@@ -27,13 +27,36 @@
     },
     "require": {
         "php": ">=7.2.0",
+        "ext-dom": "*",
+        "ext-iconv": "*",
+        "ext-json": "*",
+        "ext-libxml": "*",
         "ext-tokenizer": "*",
         "ext-xmlwriter": "*",
         "ext-simplexml": "*"
     },
     "require-dev": {
+        "maglnet/composer-require-checker": "^3.0",
         "phpunit/phpunit": "^8.0 || ^9.0"
     },
+    "suggest": {
+        "ext-posix": "More reliable detection of STDIN being a terminal device",
+        "ext-pcntl": "Allow files to be processed in parallel"
+    },
+    "autoload": {
+        "psr-4": {
+            "PHP_CodeSniffer\\": "src/"
+        },
+        "files": [
+            "autoload.php",
+            "src/Util/Tokens.php"
+        ]
+    },
+    "autoload-dev": {
+        "psr-4": {
+            "PHP_CodeSniffer\\Tests\\": "tests/"
+        }
+    },
     "bin": [
         "bin/phpcs",
         "bin/phpcbf"