diff --git a/.github/workflows/e2e.yml b/.github/workflows/e2e.yml
index 81a125b..72d6bdc 100644
--- a/.github/workflows/e2e.yml
+++ b/.github/workflows/e2e.yml
@@ -147,9 +147,6 @@ jobs:
                         repo: mimmi20/ua-device-type
                     -
                         repo: mimmi20/ua-normalizer
-                    -
-                        repo: numero2/contao-marketing-suite
-                        cdaArgs: --disable-ext-analysis --config=depcheck.php
                     -
                         repo: numero2/contao-opengraph3
                         cdaArgs: --config=depcheck.php
@@ -176,6 +173,7 @@ jobs:
                     -
                         repo: phpstan/phpstan-src
                         cdaArgs: --disable-ext-analysis --config=build/composer-dependency-analyser.php
+                        php: 8.4
                     -
                         repo: qossmic/deptrac-src
                     -
@@ -208,8 +206,6 @@ jobs:
                         repo: shipmonk-rnd/phpstan-rules
                     -
                         repo: symplify/config-transformer
-                    -
-                        repo: teamneusta/pimcore-testing-framework
                     -
                         repo: wallabag/wallabag
                         cdaArgs: --disable-ext-analysis
@@ -236,7 +232,7 @@ jobs:
                 name: Setup PHP
                 uses: shivammathur/setup-php@v2
                 with:
-                    php-version: 8.3
+                    php-version: ${{ matrix.php || '8.3' }}
                     ini-file: development
 
             -
diff --git a/scripts/refresh-e2e.php b/scripts/refresh-e2e.php
index ae5db71..8edb296 100644
--- a/scripts/refresh-e2e.php
+++ b/scripts/refresh-e2e.php
@@ -82,6 +82,7 @@ function outputYaml(array $items): void
 $result[] = [
     'repo' => 'phpstan/phpstan-src',
     'cdaArgs' => '--config=build/composer-dependency-analyser.php',
+    'php' => '8.4',
 ];
 $result[] = [
     'repo' => 'qossmic/deptrac-src',
@@ -109,6 +110,8 @@ function outputYaml(array $items): void
         || $item['repo'] === 'symplify/phpstan-rules'
         || $item['repo'] === 'contao-thememanager/core'
         || $item['repo'] === 'oveleon/contao-recommendation-bundle'
+        || $item['repo'] === 'numero2/contao-marketing-suite' // since 1.8.2 (shadow symfony/contracts via trigger_deprecation)
+        || $item['repo'] === 'teamneusta/pimcore-testing-framework' // since 1.8.2 (shadow symfony/contracts via trigger_deprecation)
     ) {
         unset($result[$index]); // failing builds
     }
diff --git a/src/Analyser.php b/src/Analyser.php
index d77416c..c27c3d7 100644
--- a/src/Analyser.php
+++ b/src/Analyser.php
@@ -123,7 +123,7 @@ class Analyser
      *
      * @var array<string, SymbolKind::*>
      */
-    private $extensionSymbolKinds = [];
+    private $knownSymbolKinds = [];
 
     /**
      * @param array<string, ClassLoader> $classLoaders vendorDir => ClassLoader (e.g. result of \Composer\Autoload\ClassLoader::getRegisteredLoaders())
@@ -392,7 +392,7 @@ private function getUsedSymbolsInFile(string $filePath): array
         }
 
         return (new UsedSymbolExtractor($code))->parseUsedSymbols(
-            $this->extensionSymbolKinds
+            $this->knownSymbolKinds
         );
     }
 
@@ -553,7 +553,7 @@ private function initExistingSymbols(Configuration $config): void
                         $this->ignoredSymbols[$constantName] = true;
                     } else {
                         $this->extensionSymbols[SymbolKind::CONSTANT][$constantName] = $extensionName;
-                        $this->extensionSymbolKinds[strtolower($constantName)] = SymbolKind::CONSTANT;
+                        $this->knownSymbolKinds[strtolower($constantName)] = SymbolKind::CONSTANT;
                     }
                 }
             }
@@ -567,6 +567,7 @@ private function initExistingSymbols(Configuration $config): void
                 if ($reflectionFunction->getExtension() === null) {
                     if (is_string($functionFilePath)) {
                         $this->definedFunctions[$functionName] = Path::normalize($functionFilePath);
+                        $this->knownSymbolKinds[$functionName] = SymbolKind::FUNCTION;
                     }
                 } else {
                     $extensionName = $this->getNormalizedExtensionName($reflectionFunction->getExtension()->name);
@@ -575,7 +576,7 @@ private function initExistingSymbols(Configuration $config): void
                         $this->ignoredSymbols[$functionName] = true;
                     } else {
                         $this->extensionSymbols[SymbolKind::FUNCTION][$functionName] = $extensionName;
-                        $this->extensionSymbolKinds[$functionName] = SymbolKind::FUNCTION;
+                        $this->knownSymbolKinds[$functionName] = SymbolKind::FUNCTION;
                     }
                 }
             }
@@ -598,7 +599,7 @@ private function initExistingSymbols(Configuration $config): void
                         $this->ignoredSymbols[$classLikeName] = true;
                     } else {
                         $this->extensionSymbols[SymbolKind::CLASSLIKE][$classLikeName] = $extensionName;
-                        $this->extensionSymbolKinds[strtolower($classLikeName)] = SymbolKind::CLASSLIKE;
+                        $this->knownSymbolKinds[strtolower($classLikeName)] = SymbolKind::CLASSLIKE;
                     }
                 }
             }
diff --git a/src/UsedSymbolExtractor.php b/src/UsedSymbolExtractor.php
index c2a5c54..e38e7c7 100644
--- a/src/UsedSymbolExtractor.php
+++ b/src/UsedSymbolExtractor.php
@@ -67,12 +67,12 @@ public function __construct(string $code)
      * It does not produce any local names in current namespace
      * - this results in very limited functionality in files without namespace
      *
-     * @param array<string, SymbolKind::*> $extensionSymbols
+     * @param array<string, SymbolKind::*> $knownSymbols
      * @return array<SymbolKind::*, array<string, list<int>>>
      * @license Inspired by https://github.com/doctrine/annotations/blob/2.0.0/lib/Doctrine/Common/Annotations/TokenParser.php
      */
     public function parseUsedSymbols(
-        array $extensionSymbols
+        array $knownSymbols
     ): array
     {
         $usedSymbols = [];
@@ -124,7 +124,7 @@ public function parseUsedSymbols(
                     case PHP_VERSION_ID >= 80000 ? T_NAME_FULLY_QUALIFIED : -1:
                         $symbolName = $this->normalizeBackslash($token[1]);
                         $lowerSymbolName = strtolower($symbolName);
-                        $kind = $extensionSymbols[$lowerSymbolName] ?? $this->getFqnSymbolKind($this->pointer - 2, $this->pointer, $inAttributeSquareLevel !== null);
+                        $kind = $knownSymbols[$lowerSymbolName] ?? $this->getFqnSymbolKind($this->pointer - 2, $this->pointer, $inAttributeSquareLevel !== null);
                         $usedSymbols[$kind][$symbolName][] = $token[2];
                         break;
 
@@ -140,7 +140,7 @@ public function parseUsedSymbols(
                         }
 
                         $lowerSymbolName = strtolower($symbolName);
-                        $kind = $extensionSymbols[$lowerSymbolName] ?? $this->getFqnSymbolKind($this->pointer - 2, $this->pointer, $inAttributeSquareLevel !== null);
+                        $kind = $knownSymbols[$lowerSymbolName] ?? $this->getFqnSymbolKind($this->pointer - 2, $this->pointer, $inAttributeSquareLevel !== null);
                         $usedSymbols[$kind][$symbolName][] = $token[2];
 
                         break;
@@ -160,9 +160,9 @@ public function parseUsedSymbols(
                             $kind = $useStatementKinds[$name];
                             $usedSymbols[$kind][$symbolName][] = $token[2];
 
-                        } elseif (isset($extensionSymbols[$lowerName])) {
+                        } elseif (isset($knownSymbols[$lowerName])) {
                             $symbolName = $name;
-                            $kind = $extensionSymbols[$lowerName];
+                            $kind = $knownSymbols[$lowerName];
 
                             if (!$inGlobalScope && $kind === SymbolKind::CLASSLIKE) {
                                 break; // cannot use class-like symbols in non-global scope when not imported
@@ -192,7 +192,7 @@ public function parseUsedSymbols(
                         $lowerSymbolName = strtolower($symbolName);
 
                         if ($symbolName !== '') { // e.g. \array (NS separator followed by not-a-name)
-                            $kind = $extensionSymbols[$lowerSymbolName] ?? $this->getFqnSymbolKind($pointerBeforeName, $this->pointer - 1, false);
+                            $kind = $knownSymbols[$lowerSymbolName] ?? $this->getFqnSymbolKind($pointerBeforeName, $this->pointer - 1, false);
                             $usedSymbols[$kind][$symbolName][] = $token[2];
                         }
 
@@ -213,9 +213,9 @@ public function parseUsedSymbols(
                             $kind = $useStatementKinds[$name];
                             $usedSymbols[$kind][$symbolName][] = $token[2];
 
-                        } elseif (isset($extensionSymbols[$lowerName])) {
+                        } elseif (isset($knownSymbols[$lowerName])) {
                             $symbolName = $name;
-                            $kind = $extensionSymbols[$lowerName];
+                            $kind = $knownSymbols[$lowerName];
 
                             if (!$inGlobalScope && $kind === SymbolKind::CLASSLIKE) {
                                 break; // cannot use class-like symbols in non-global scope when not imported
diff --git a/tests/UsedSymbolExtractorTest.php b/tests/UsedSymbolExtractorTest.php
index ebb2e46..646a274 100644
--- a/tests/UsedSymbolExtractorTest.php
+++ b/tests/UsedSymbolExtractorTest.php
@@ -72,6 +72,12 @@ public function provideVariants(): iterable
                     'PHPUnit\Framework\Error' => [14],
                     'LogicException' => [15, 20],
                 ],
+                SymbolKind::FUNCTION => [
+                    'user_defined_function' => [38],
+                ],
+            ],
+            [
+                'user_defined_function' => SymbolKind::FUNCTION,
             ],
         ];
 
@@ -113,7 +119,6 @@ public function provideVariants(): iterable
         ];
 
         yield 'global namespace' => [
-
             __DIR__ . '/data/not-autoloaded/used-symbols/global-namespace.php',
             [
                 SymbolKind::CLASSLIKE => [
@@ -122,8 +127,12 @@ public function provideVariants(): iterable
                 ],
                 SymbolKind::FUNCTION => [
                     'PHPUnit\Framework\assertSame' => [7],
+                    'user_defined_function' => [12],
                 ],
             ],
+            [
+                strtolower('user_defined_function') => SymbolKind::FUNCTION,
+            ],
         ];
 
         yield 'curly braces' => [
diff --git a/tests/data/not-autoloaded/used-symbols/global-namespace.php b/tests/data/not-autoloaded/used-symbols/global-namespace.php
index a6e0929..737966a 100644
--- a/tests/data/not-autoloaded/used-symbols/global-namespace.php
+++ b/tests/data/not-autoloaded/used-symbols/global-namespace.php
@@ -9,6 +9,6 @@
 class Foo {
     public function someFunction(string $foo): void
     {
-
+        user_defined_function();
     }
 }
diff --git a/tests/data/not-autoloaded/used-symbols/various-usages.php b/tests/data/not-autoloaded/used-symbols/various-usages.php
index 46d393c..e5618c1 100644
--- a/tests/data/not-autoloaded/used-symbols/various-usages.php
+++ b/tests/data/not-autoloaded/used-symbols/various-usages.php
@@ -35,7 +35,7 @@ class Foo {
 
     public function foo(Error $error): void // not PHPUnit\Framework\Error anymore
     {
-
+        user_defined_function();
     }
 
 }