diff --git a/src/BitArray/BitArray.php b/src/BitArray/BitArray.php
index 06cfbec..e17d8ca 100644
--- a/src/BitArray/BitArray.php
+++ b/src/BitArray/BitArray.php
@@ -636,7 +636,7 @@ public function applyComplement()
         $length = strlen($this->data);
 
         for ($index = 0; $index < $length; $index++) {
-            $this->data[$index] = chr(~ ord($this->data[$index]));
+            $this->data[$index] = chr((~ ord($this->data[$index])) & 0xFF);
         }
 
         return $this->restrict();
diff --git a/tests/BitArray/BitArrayTest.php b/tests/BitArray/BitArrayTest.php
index 5f29ec1..b53f740 100644
--- a/tests/BitArray/BitArrayTest.php
+++ b/tests/BitArray/BitArrayTest.php
@@ -747,6 +747,41 @@ public function testApplyComplement()
         );
     }
 
+    /**
+     * Tests BitArray::applyComplement does not trigger a deprecation on PHP 8.5
+     *
+     * @return void
+     */
+    public function testApplyComplementDoesNotTriggerDeprecation()
+    {
+        if (PHP_VERSION_ID < 80500) {
+            $this->markTestSkipped('This test requires PHP 8.5 or later');
+        }
+
+        set_error_handler(
+            static function (
+                int $severity,
+                string $message,
+                string $filename,
+                int $line
+            ): never {
+                throw new \ErrorException($message, 0, $severity, $filename, $line);
+            },
+            E_DEPRECATED
+        );
+
+        try {
+            $bits = BitArray::fromString('10011');
+
+            $this->assertEquals(
+                '01100',
+                (string) $bits->applyComplement()
+            );
+        } finally {
+            restore_error_handler();
+        }
+    }
+
     /**
      * Tests  BitArray::applyOr
      *