diff --git a/src/FixtureBuilder/ExpressionLanguage/Lexer/FunctionTreeTokenizer.php b/src/FixtureBuilder/ExpressionLanguage/Lexer/FunctionTreeTokenizer.php
index 5ec3ca266..197402fa4 100644
--- a/src/FixtureBuilder/ExpressionLanguage/Lexer/FunctionTreeTokenizer.php
+++ b/src/FixtureBuilder/ExpressionLanguage/Lexer/FunctionTreeTokenizer.php
@@ -48,7 +48,7 @@ final class FunctionTreeTokenizer
     public function tokenize(string $value): array
     {
         $value = preg_replace(
-            '/(.*?)<((?:.*?:)?(?:\p{L}|[0-9])+?)\((.*?)/',
+            '/(.*?)<((?:.*?:)?(?:\p{L}|_|[0-9])+?)\((.*?)/',
             sprintf('$1%1$sFUNCTION_START__$2__%1$s$3', self::DELIMITER),
             $value
         );
diff --git a/src/FixtureBuilder/ExpressionLanguage/Lexer/SubPatternsLexer.php b/src/FixtureBuilder/ExpressionLanguage/Lexer/SubPatternsLexer.php
index 78067672c..8a98eae83 100644
--- a/src/FixtureBuilder/ExpressionLanguage/Lexer/SubPatternsLexer.php
+++ b/src/FixtureBuilder/ExpressionLanguage/Lexer/SubPatternsLexer.php
@@ -46,7 +46,7 @@ final class SubPatternsLexer implements LexerInterface
         '/^(<\(.+\)>)/' => TokenType::IDENTITY_TYPE,
         '/^(<\S+\(.*\)>)/' => TokenType::FUNCTION_TYPE,
         '/^(<\S+>)/' => null,
-        '/^(\[[^\[\]]+\])/' => TokenType::STRING_ARRAY_TYPE,
+        '/^(\[[^\[\]]*\])/' => TokenType::STRING_ARRAY_TYPE,
         '/^(@[^\ @\{\<]+\(.*\))/' => self::REFERENCE_LEXER, // Function with text
         '/^(@[^\ @\<]+\{.*\}->\S+\(.*\))/' => self::REFERENCE_LEXER, // Range or list with function
         '/^(@[^\ @\<]+\{.*\}->[^\(\)\ \{]+)/' => self::REFERENCE_LEXER, // Range or list with property
diff --git a/tests/Loader/LoaderIntegrationTest.php b/tests/Loader/LoaderIntegrationTest.php
index 2a0c9ceb0..05c8a0415 100644
--- a/tests/Loader/LoaderIntegrationTest.php
+++ b/tests/Loader/LoaderIntegrationTest.php
@@ -2832,5 +2832,23 @@ public function provideFixturesToGenerate()
                 ],
             ],
         ];
+
+        yield '[function] call nested PHP native function' => [
+            [
+                \stdClass::class => [
+                    'dummy' => [
+                        'foo' => '<json_encode([])>',
+                    ],
+                ],
+            ],
+            [
+                'parameters' => [],
+                'objects' => [
+                    'dummy' => StdClassFactory::create([
+                        'foo' => '[]',
+                    ]),
+                ],
+            ],
+        ];
     }
 }