diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index aed4718..aaf8e27 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -11,7 +11,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php-version: ['7.4', '8.0', '8.1', '8.2', '8.3', '8.4']
+        php-version: ['7.4', '8.0', '8.1', '8.2', '8.3', '8.4', '8.5']
         os: [ubuntu-latest]
     runs-on: ${{ matrix.os }}
 
diff --git a/src/Util.php b/src/Util.php
index b4220e9..0c4cf31 100644
--- a/src/Util.php
+++ b/src/Util.php
@@ -10,7 +10,9 @@ function hashCode(string $s): int
     }
     for ($i = 0; $i < strlen($s); $i++) {
         $chr = ord($s[$i]);
-        $hash = (int) (($hash << 5) - $hash + $chr);
+        // Use bitwise operations to ensure we stay within 32-bit signed integer range
+        // This prevents float conversion and maintains compatibility with PHP 8.5+
+        $hash = ((($hash << 5) - $hash) + $chr) & 0x7FFFFFFF;
     }
     return $hash;
 }