diff --git a/phpseclib/Math/BigInteger/Engines/PHP32.php b/phpseclib/Math/BigInteger/Engines/PHP32.php
index d4987329..27c34acb 100644
--- a/phpseclib/Math/BigInteger/Engines/PHP32.php
+++ b/phpseclib/Math/BigInteger/Engines/PHP32.php
@@ -82,10 +82,10 @@ class PHP32 extends PHP
             }
             $step = count($vals) & 3;
             if ($step) {
-                $digit = floor($digit / 2 ** (2 * $step));
+                $digit = (int) floor($digit / 2 ** (2 * $step));
             }
             if ($step != 3) {
-                $digit &= static::MAX_DIGIT;
+                $digit = (int) fmod($digit, static::BASE_FULL);
                 $i++;
             }
             $vals[] = $digit;