diff --git a/phpseclib/File/ASN1.php b/phpseclib/File/ASN1.php
index 90490b3d..34430c3e 100644
--- a/phpseclib/File/ASN1.php
+++ b/phpseclib/File/ASN1.php
@@ -503,7 +503,7 @@ class ASN1
         switch (true) {
             case $mapping['type'] == self::TYPE_ANY:
                 $intype = $decoded['type'];
-                if (isset($decoded['constant']) || !isset($this->ANYmap[$intype]) || ($this->encoded[$decoded['start']] & 0x20)) {
+                if (isset($decoded['constant']) || !isset($this->ANYmap[$intype]) || (ord($this->encoded[$decoded['start']]) & 0x20)) {
                     return new Element(substr($this->encoded, $decoded['start'], $decoded['length']));
                 }
                 $inmap = $this->ANYmap[$intype];
diff --git a/tests/Unit/File/X509/CSRTest.php b/tests/Unit/File/X509/CSRTest.php
index 6e4b827d..849b788e 100644
--- a/tests/Unit/File/X509/CSRTest.php
+++ b/tests/Unit/File/X509/CSRTest.php
@@ -6,6 +6,7 @@
  */
 
 use phpseclib\File\X509;
+use phpseclib\Crypt\RSA;
 
 class Unit_File_X509_CSRTest extends PhpseclibTestCase
 {
@@ -93,4 +94,28 @@ draiRBZruwMPwPIP
 
         $this->assertInternalType('array', $csr);
     }
+
+    // on PHP 7.1, with older versions of phpseclib, this would produce a "A non-numeric value encountered" warning
+    public function testNewCSR()
+    {
+        $rsa = new RSA();
+        $x509 = new X509();
+
+        $rsa->loadKey('-----BEGIN RSA PRIVATE KEY-----
+MIICXAIBAAKBgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4eCZ0FPqri0cb2JZfXJ/DgYSF6vUp
+wmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RKNUSesmQRMSGkVb1/3j+skZ6UtW+5u09lHNsj6tQ5
+1s1SPrCBkedbNf0Tp0GbMJDyR4e9T04ZZwIDAQABAoGAFijko56+qGyN8M0RVyaRAXz++xTqHBLh
+3tx4VgMtrQ+WEgCjhoTwo23KMBAuJGSYnRmoBZM3lMfTKevIkAidPExvYCdm5dYq3XToLkkLv5L2
+pIIVOFMDG+KESnAFV7l2c+cnzRMW0+b6f8mR1CJzZuxVLL6Q02fvLi55/mbSYxECQQDeAw6fiIQX
+GukBI4eMZZt4nscy2o12KyYner3VpoeE+Np2q+Z3pvAMd/aNzQ/W9WaI+NRfcxUJrmfPwIGm63il
+AkEAxCL5HQb2bQr4ByorcMWm/hEP2MZzROV73yF41hPsRC9m66KrheO9HPTJuo3/9s5p+sqGxOlF
+L0NDt4SkosjgGwJAFklyR1uZ/wPJjj611cdBcztlPdqoxssQGnh85BzCj/u3WqBpE2vjvyyvyI5k
+X6zk7S0ljKtt2jny2+00VsBerQJBAJGC1Mg5Oydo5NwD6BiROrPxGo2bpTbu/fhrT8ebHkTz2epl
+U9VQQSQzY1oZMVX8i1m5WUTLPz2yLJIBQVdXqhMCQBGoiuSoSjafUhV7i1cEGpb88h5NBYZzWXGZ
+37sJ5QsW+sJyoNde3xH8vdXhzU7eT82D6X/scw9RZz+/6rCJ4p0=
+-----END RSA PRIVATE KEY-----');
+        $x509->setPrivateKey($rsa);
+        $x509->setDN(array('cn' => 'ncgamers.org'));
+        $x509->saveCSR($x509->signCSR('sha256WithRSAEncryption'), X509::FORMAT_DER);
+    }
 }