diff --git a/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/Barrett.php b/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/Barrett.php
index 7237c5ac..f858ce17 100644
--- a/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/Barrett.php
+++ b/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/Barrett.php
@@ -61,7 +61,7 @@ abstract class Barrett extends Base
      *
      * @param string $n
      * @param string $m
-     * @return array
+     * @return array|string
      */
     protected static function reduce($n, $m)
     {
diff --git a/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/EvalBarrett.php b/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/EvalBarrett.php
index 2ab676e6..58374b3d 100644
--- a/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/EvalBarrett.php
+++ b/phpseclib/Math/BigInteger/Engines/BCMath/Reductions/EvalBarrett.php
@@ -55,7 +55,7 @@ abstract class EvalBarrett extends Base
      *
      * @param array $m
      * @param string $class
-     * @return callable
+     * @return callable|void
      */
     protected static function generateCustomReduction(BCMath $m, $class)
     {