diff --git a/resources/functionMap.php b/resources/functionMap.php
index b4a78d684e..f3b563aa48 100644
--- a/resources/functionMap.php
+++ b/resources/functionMap.php
@@ -8190,7 +8190,7 @@
 'preg_match_all' => ['0|positive-int|false|null', 'pattern'=>'string', 'subject'=>'string', '&w_subpatterns='=>'array', 'flags='=>'int', 'offset='=>'int'],
 'preg_quote' => ['string', 'str'=>'string', 'delim_char='=>'string'],
 'preg_replace' => ['string|array|null', 'regex'=>'string|array', 'replace'=>'string|array', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
-'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable(array<int|string, string>):string', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
+'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable(array<int|string, string|null>):string', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
 'preg_replace_callback_array' => ['string|array|null', 'pattern'=>'array<string,callable>', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int'],
 'preg_split' => ['list<string>|list<array{string, int<0, max>}>|false', 'pattern'=>'string', 'subject'=>'string', 'limit='=>'?int', 'flags='=>'int'],
 'prev' => ['mixed', '&rw_array_arg'=>'array|object'],
diff --git a/resources/functionMap_php74delta.php b/resources/functionMap_php74delta.php
index ac48bed6ff..bade1e3f2d 100644
--- a/resources/functionMap_php74delta.php
+++ b/resources/functionMap_php74delta.php
@@ -44,7 +44,7 @@
 		'opcache_get_configuration' => ['array{directives: array{\'opcache.enable\': bool, \'opcache.enable_cli\': bool, \'opcache.use_cwd\': bool, \'opcache.validate_timestamps\': bool, \'opcache.validate_permission\': bool, \'opcache.validate_root\'?: bool, \'opcache.dups_fix\': bool, \'opcache.revalidate_path\': bool, \'opcache.log_verbosity_level\': int, \'opcache.memory_consumption\': int, \'opcache.interned_strings_buffer\': int, \'opcache.max_accelerated_files\': int, \'opcache.max_wasted_percentage\': float, \'opcache.consistency_checks\': int, \'opcache.force_restart_timeout\': int, \'opcache.revalidate_freq\': int, \'opcache.preferred_memory_model\': string, \'opcache.blacklist_filename\': string, \'opcache.max_file_size\': int, \'opcache.error_log\': string, \'opcache.protect_memory\': bool, \'opcache.save_comments\': bool, \'opcache.enable_file_override\': bool, \'opcache.optimization_level\': int, \'opcache.lockfile_path\'?: string, \'opcache.mmap_base\'?: string, \'opcache.file_cache\': string, \'opcache.file_cache_only\': bool, \'opcache.file_cache_consistency_checks\': bool, \'opcache.file_cache_fallback\'?: bool, \'opcache.file_update_protection\': int, \'opcache.opt_debug_level\': int, \'opcache.restrict_api\': string, \'opcache.huge_code_pages\'?: bool, \'opcache.preload\': string, \'opcache.preload_user\'?: string, \'opcache.cache_id\'?: string}, version: array{version: non-empty-string, opcache_product_name: non-empty-string}, blacklist: list<string>}|false'],
 		'password_algos' => ['list<string>'],
 		'password_needs_rehash' => ['bool', 'hash'=>'string', 'algo'=>'string|null', 'options='=>'array'],
-		'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable(array<int|string, string>):string', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int', 'flags='=>'int'],
+		'preg_replace_callback' => ['string|array|null', 'regex'=>'string|array', 'callback'=>'callable(array<int|string, string|null>):string', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int', 'flags='=>'int'],
 		'preg_replace_callback_array' => ['string|array|null', 'pattern'=>'array<string,callable>', 'subject'=>'string|array', 'limit='=>'int', '&w_count='=>'int', 'flags='=>'int'],
 		'sapi_windows_set_ctrl_handler' => ['bool', 'callable'=>'callable(int):void', 'add='=>'bool'],
 		'ReflectionProperty::getType' => ['?ReflectionType'],
diff --git a/tests/PHPStan/Analyser/nsrt/preg_replace_callback_shapes.php b/tests/PHPStan/Analyser/nsrt/preg_replace_callback_shapes.php
index 7bd70492ee..b9aa8f5482 100644
--- a/tests/PHPStan/Analyser/nsrt/preg_replace_callback_shapes.php
+++ b/tests/PHPStan/Analyser/nsrt/preg_replace_callback_shapes.php
@@ -2,6 +2,7 @@
 
 namespace PregReplaceCallbackMatchShapes;
 
+use function PHPStan\Testing\assertNativeType;
 use function PHPStan\Testing\assertType;
 
 function (string $s): void {
@@ -56,3 +57,18 @@ function ($matches) {
 		$string
 	);
 }
+
+function bug14904(string $string): void {
+	preg_replace_callback(
+		'/a|(?<b>b)/',
+		function (array $match): string {
+			assertType("array{0: non-empty-string, b: 'b'|null, 1: 'b'|null}", $match);
+			assertNativeType('array<int|string, string|null>', $match);
+			return '';
+		},
+		$string,
+		-1,
+		$count,
+		PREG_UNMATCHED_AS_NULL
+	);
+}
diff --git a/tests/PHPStan/Rules/Comparison/StrictComparisonOfDifferentTypesRuleTest.php b/tests/PHPStan/Rules/Comparison/StrictComparisonOfDifferentTypesRuleTest.php
index 436a0125a5..f8f38214d8 100644
--- a/tests/PHPStan/Rules/Comparison/StrictComparisonOfDifferentTypesRuleTest.php
+++ b/tests/PHPStan/Rules/Comparison/StrictComparisonOfDifferentTypesRuleTest.php
@@ -673,6 +673,13 @@ public function testBug6260(): void
 		$this->analyse([__DIR__ . '/data/bug-6260.php'], []);
 	}
 
+	#[RequiresPhp('>= 8.0.0')]
+	public function testBug14904(): void
+	{
+		$this->treatPhpDocTypesAsCertain = false;
+		$this->analyse([__DIR__ . '/data/bug-14904.php'], []);
+	}
+
 	public function testBug8736(): void
 	{
 		$this->analyse([__DIR__ . '/data/bug-8736.php'], []);
diff --git a/tests/PHPStan/Rules/Comparison/data/bug-14904.php b/tests/PHPStan/Rules/Comparison/data/bug-14904.php
new file mode 100644
index 0000000000..adbf20f150
--- /dev/null
+++ b/tests/PHPStan/Rules/Comparison/data/bug-14904.php
@@ -0,0 +1,18 @@
+<?php declare(strict_types = 1); // lint >= 8.0
+
+namespace Bug14904;
+
+function doFoo(): void
+{
+	preg_replace_callback(
+		'/a|(?<b>b)/',
+		function (array $match): string {
+			if ($match['b'] !== null) {
+				return 'aa';
+			}
+			return 'possible?';
+		},
+		'abcd',
+		flags: PREG_UNMATCHED_AS_NULL,
+	);
+}