diff --git a/.styleci.yml b/.styleci.yml
index 6cf29b27..f6dbf717 100644
--- a/.styleci.yml
+++ b/.styleci.yml
@@ -18,7 +18,6 @@ enabled:
   - declare_strict_types
   - dir_constant
   - empty_loop_body_braces
-  - function_to_constant
   - hash_to_slash_comment
   - integer_literal_case
   - is_null
diff --git a/src/http/ErrorHandler.php b/src/http/ErrorHandler.php
index 872e70d0..56df7d3d 100644
--- a/src/http/ErrorHandler.php
+++ b/src/http/ErrorHandler.php
@@ -119,7 +119,7 @@ public function handleException($exception): Response
 
         $this->unregister();
 
-        if (PHP_SAPI !== 'cli') {
+        if (php_sapi_name() !== 'cli') {
             $statusCode = 500;
 
             if ($exception instanceof HttpException) {
diff --git a/tests/http/ErrorHandlerTest.php b/tests/http/ErrorHandlerTest.php
index 683f95dd..e339a648 100644
--- a/tests/http/ErrorHandlerTest.php
+++ b/tests/http/ErrorHandlerTest.php
@@ -5,11 +5,13 @@
 namespace yii2\extensions\psrbridge\tests\http;
 
 use PHPUnit\Framework\Attributes\Group;
+use PHPUnit\Framework\Attributes\TestWith;
 use RuntimeException;
 use Throwable;
 use yii\base\{Exception, UserException};
 use yii\web\HttpException;
 use yii2\extensions\psrbridge\http\{ErrorHandler, Response};
+use yii2\extensions\psrbridge\tests\support\stub\HTTPFunctions;
 use yii2\extensions\psrbridge\tests\TestCase;
 
 use function str_repeat;
@@ -17,6 +19,13 @@
 #[Group('http')]
 final class ErrorHandlerTest extends TestCase
 {
+    protected function tearDown(): void
+    {
+        HTTPFunctions::reset();
+
+        parent::tearDown();
+    }
+
     public function testHandleExceptionResetsState(): void
     {
         $errorHandler = new ErrorHandler();
@@ -97,8 +106,12 @@ public function testHandleExceptionWithGenericException(): void
         );
     }
 
-    public function testHandleExceptionWithHttpException(): void
+    #[TestWith(['apache'])]
+    #[TestWith(['cli'])]
+    public function testHandleExceptionWithHttpException(string $sapi): void
     {
+        HTTPFunctions::set_sapi($sapi);
+
         $errorHandler = new ErrorHandler();
 
         $errorHandler->discardExistingOutput = false;
@@ -116,6 +129,11 @@ public function testHandleExceptionWithHttpException(): void
             $response->data,
             'Should set response data for HTTP exception.',
         );
+        self::assertSame(
+            $sapi,
+            HTTPFunctions::php_sapi_name(),
+            "Should return correct SAPI name '{$sapi}' for 'HttpException'.",
+        );
     }
 
     public function testHandleExceptionWithLongMessage(): void
diff --git a/tests/support/MockerExtension.php b/tests/support/MockerExtension.php
index e4c21b8b..9cd9b5b0 100644
--- a/tests/support/MockerExtension.php
+++ b/tests/support/MockerExtension.php
@@ -73,6 +73,11 @@ public static function load(): void
                     $line,
                 ),
             ],
+            [
+                'namespace' => 'yii2\extensions\psrbridge\http',
+                'name' => 'php_sapi_name',
+                'function' => static fn(): string => HTTPFunctions::php_sapi_name(),
+            ],
             [
                 'namespace' => 'yii2\extensions\psrbridge\adapter',
                 'name' => 'stream_get_contents',
diff --git a/tests/support/stub/HTTPFunctions.php b/tests/support/stub/HTTPFunctions.php
index 85f9c3a8..4d5f187c 100644
--- a/tests/support/stub/HTTPFunctions.php
+++ b/tests/support/stub/HTTPFunctions.php
@@ -15,19 +15,20 @@
  * Provides controlled replacements for core PHP HTTP header and response functions to facilitate testing of HTTP
  * emitter and response-related code without actual header output or side effects.
  *
- * This class allows tests to simulate and inspect HTTP header operations, response codes, and output flushing by
- * maintaining internal state and exposing methods to manipulate and query that state.
+ * This class allows tests to simulate and inspect HTTP header operations, response codes, output flushing,
+ * and SAPI name retrieval by maintaining internal state and exposing methods to manipulate and query that state.
  *
- * It enables validation of emitter logic, header management, and response code handling in isolation from PHP's global
- * state.
+ * It enables validation of emitter logic, header management, response code handling, and SAPI simulation in isolation
+ * from PHP global state.
  *
  * Key features.
  * - Complete simulation of {@see \header()}, {@see \headers_sent()}, {@see \header_remove()}, {@see \headers_list()},
- *   and {@see \http_response_code()}
+ *   {@see \http_response_code()}, and {@see php_sapi_name()} for test reliability.
  * - Consistent behavior matching PHP's native functions for test reliability.
  * - File and line tracking for headers_sent simulation.
  * - Header inspection and manipulation for assertions.
  * - Simulated output flushing and flush count tracking.
+ * - SAPI name simulation for emitter and environment testing.
  * - State reset capability for test isolation and repeatability.
  *
  * @copyright Copyright (C) 2025 Terabytesoftw.
@@ -67,6 +68,11 @@ final class HTTPFunctions
      */
     private static int $responseCode = 200;
 
+    /**
+     * Tracks the current SAPI name for simulation.
+     */
+    private static string $sapi = 'cli';
+
     /**
      * Controls whether stream_get_contents should fail.
      */
@@ -154,6 +160,11 @@ public static function http_response_code(int|null $response_code = 0): int
         return self::$responseCode;
     }
 
+    public static function php_sapi_name(): string
+    {
+        return self::$sapi;
+    }
+
     public static function reset(): void
     {
         self::$flushedTimes = 0;
@@ -162,6 +173,7 @@ public static function reset(): void
         self::$headersSentFile = '';
         self::$headersSentLine = 0;
         self::$responseCode = 200;
+        self::$sapi = 'cli';
         self::$streamGetContentsShouldFail = false;
     }
 
@@ -172,6 +184,11 @@ public static function set_headers_sent(bool $value = false, string $file = '',
         self::$headersSentLine = $line;
     }
 
+    public static function set_sapi(string $sapi): void
+    {
+        self::$sapi = $sapi;
+    }
+
     public static function set_stream_get_contents_should_fail(bool $shouldFail = true): void
     {
         self::$streamGetContentsShouldFail = $shouldFail;