diff --git a/phpseclib/Crypt/RSA.php b/phpseclib/Crypt/RSA.php
index 770c67478..c5f697701 100644
--- a/phpseclib/Crypt/RSA.php
+++ b/phpseclib/Crypt/RSA.php
@@ -3035,6 +3035,9 @@ function _emsa_pkcs1_v1_5_encode_without_null($m, $emLen)
                 break;
             case 'sha512':
                 $t = pack('H*', '304f300b06096086480165030402030440');
+                break;
+            default:
+                return false;
         }
         $t.= $h;
         $tLen = strlen($t);