diff --git a/lib/Saml2/Utils.php b/lib/Saml2/Utils.php
index 1a7f85f3..c0e35346 100644
--- a/lib/Saml2/Utils.php
+++ b/lib/Saml2/Utils.php
@@ -208,27 +208,29 @@ public static function treeCopyReplace(DomNode $targetNode, DomNode $sourceNode,
     /**
      * Returns a x509 cert (adding header & footer if required).
      *
-     * @param string  $cert  A x509 unformated cert
-     * @param bool    $heads True if we want to include head and footer
+     * @param string  $x509cert  A x509 unformated cert
+     * @param bool    $heads     True if we want to include head and footer
      *
      * @return string $x509 Formatted cert
      */
+     public static function formatCert($x509cert, $heads = true)
+     {
+         if (is_null($x509cert)) {
+           return;
+         }
 
-    public static function formatCert($cert, $heads = true)
-    {
-        $x509cert = str_replace(array("\x0D", "\r", "\n"), "", $cert);
-        if (!empty($x509cert)) {
-            $x509cert = str_replace('-----BEGIN CERTIFICATE-----', "", $x509cert);
-            $x509cert = str_replace('-----END CERTIFICATE-----', "", $x509cert);
-            $x509cert = str_replace(' ', '', $x509cert);
-
-            if ($heads) {
-                $x509cert = "-----BEGIN CERTIFICATE-----\n".chunk_split($x509cert, 64, "\n")."-----END CERTIFICATE-----\n";
-            }
+         if (strpos($x509cert, '-----BEGIN CERTIFICATE-----') !== false) {
+             $x509cert = static::getStringBetween($x509cert, '-----BEGIN CERTIFICATE-----', '-----END CERTIFICATE-----');
+         }
 
-        }
-        return $x509cert;
-    }
+         $x509cert = str_replace(array("\x0d", "\r", "\n", " "), '', $x509cert);
+
+         if ($heads && $x509cert !== '') {
+             $x509cert = "-----BEGIN CERTIFICATE-----\n".chunk_split($x509cert, 64, "\n")."-----END CERTIFICATE-----\n";
+         }
+
+         return $x509cert;
+     }
 
     /**
      * Returns a private key (adding header & footer if required).
diff --git a/tests/certs/with.comment.crt b/tests/certs/with.comment.crt
new file mode 100644
index 00000000..ed0e9729
--- /dev/null
+++ b/tests/certs/with.comment.crt
@@ -0,0 +1,17 @@
+# certificate comments should be ignored
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/tests/src/OneLogin/Saml2/AuthTest.php b/tests/src/OneLogin/Saml2/AuthTest.php
index 908a7994..86d4e30b 100644
--- a/tests/src/OneLogin/Saml2/AuthTest.php
+++ b/tests/src/OneLogin/Saml2/AuthTest.php
@@ -817,22 +817,16 @@ public function testProcessSLORequestRelayState()
         $_GET['SAMLRequest'] = $message;
         $_GET['RelayState'] = 'http://relaystate.com';
 
-        try {
-            $this->_auth->setStrict(true);
-            $this->_auth->processSLO(false);
-            $this->assertFalse(true);
-        } catch (Exception $e) {
-            $this->assertContains('Cannot modify header information', $e->getMessage());
-            $trace = $e->getTrace();
-            $targetUrl = getUrlFromRedirect($trace);
-            $parsedQuery = getParamsFromUrl($targetUrl);
+        $this->_auth->setStrict(true);
+        $targetUrl = $this->_auth->processSLO(false, null, false, null, true);
 
-            $sloUrl = $this->_settingsInfo['idp']['singleLogoutService']['url'];
-            $this->assertContains($sloUrl, $targetUrl);
-            $this->assertArrayHasKey('SAMLResponse', $parsedQuery);
-            $this->assertArrayHasKey('RelayState', $parsedQuery);
-            $this->assertEquals('http://relaystate.com', $parsedQuery['RelayState']);
-        }
+        $parsedQuery = getParamsFromUrl($targetUrl);
+
+        $sloResponseUrl = $this->_settingsInfo['idp']['singleLogoutService']['responseUrl'];
+        $this->assertContains($sloResponseUrl, $targetUrl);
+        $this->assertArrayHasKey('SAMLResponse', $parsedQuery);
+        $this->assertArrayHasKey('RelayState', $parsedQuery);
+        $this->assertEquals('http://relaystate.com', $parsedQuery['RelayState']);
     }
 
     /**
@@ -860,28 +854,22 @@ public function testProcessSLORequestSignedResponse()
         $plainMessage = str_replace('http://stuff.com/endpoints/endpoints/sls.php', $currentURL, $plainMessage);
         $message = base64_encode(gzdeflate($plainMessage));
 
+        unset($_GET['SAMLResponse']);
         $_GET['SAMLRequest'] = $message;
         $_GET['RelayState'] = 'http://relaystate.com';
 
-        try {
-            $auth->setStrict(true);
-            $auth->processSLO(false);
-            $this->assertFalse(true);
-        } catch (Exception $e) {
-            $this->assertContains('Cannot modify header information', $e->getMessage());
-            $trace = $e->getTrace();
-            $targetUrl = getUrlFromRedirect($trace);
-            $parsedQuery = getParamsFromUrl($targetUrl);
-
-            $sloUrl = $settingsInfo['idp']['singleLogoutService']['url'];
-            $this->assertContains($sloUrl, $targetUrl);
-            $this->assertArrayHasKey('SAMLResponse', $parsedQuery);
-            $this->assertArrayHasKey('RelayState', $parsedQuery);
-            $this->assertArrayHasKey('SigAlg', $parsedQuery);
-            $this->assertArrayHasKey('Signature', $parsedQuery);
-            $this->assertEquals('http://relaystate.com', $parsedQuery['RelayState']);
-            $this->assertEquals(XMLSecurityKey::RSA_SHA1, $parsedQuery['SigAlg']);
-        }
+        $auth->setStrict(true);
+        $targetUrl = $auth->processSLO(false, null, false, null, true);
+        $parsedQuery = getParamsFromUrl($targetUrl);
+
+        $sloUrl = $settingsInfo['idp']['singleLogoutService']['responseUrl'];
+        $this->assertContains($sloUrl, $targetUrl);
+        $this->assertArrayHasKey('SAMLResponse', $parsedQuery);
+        $this->assertArrayHasKey('RelayState', $parsedQuery);
+        $this->assertArrayHasKey('SigAlg', $parsedQuery);
+        $this->assertArrayHasKey('Signature', $parsedQuery);
+        $this->assertEquals('http://relaystate.com', $parsedQuery['RelayState']);
+        $this->assertEquals(XMLSecurityKey::RSA_SHA1, $parsedQuery['SigAlg']);
     }
 
     /**
diff --git a/tests/src/OneLogin/Saml2/UtilsTest.php b/tests/src/OneLogin/Saml2/UtilsTest.php
index c3226c36..b2fcbb8b 100644
--- a/tests/src/OneLogin/Saml2/UtilsTest.php
+++ b/tests/src/OneLogin/Saml2/UtilsTest.php
@@ -46,7 +46,7 @@ public function testLoadXML()
         try {
             $res1 = OneLogin_Saml2_Utils::loadXML($dom, $metadataUnloaded);
             $this->assertFalse($res1);
-        } catch (Exception $e) {
+        } catch (\Exception $e) {
           $this->assertEquals('DOMDocument::loadXML(): Premature end of data in tag EntityDescriptor line 1 in Entity, line: 1', $e->getMessage());
         }
 
@@ -206,6 +206,11 @@ public function testFormatCert()
         $this->assertNotContains('-----END CERTIFICATE-----', $formatedCert6);
         $this->assertEquals(strlen($cert2), 860);
 
+        $cert = file_get_contents(TEST_ROOT.'/certs/with.comment.crt');
+        $formatedCert7 = OneLogin_Saml2_Utils::formatCert($cert, true);
+        $this->assertContains('-----BEGIN CERTIFICATE-----', $formatedCert7);
+        $this->assertContains('-----END CERTIFICATE-----', $formatedCert7);
+        $this->assertNotContains('comments', $formatedCert7);
     }
 
     /**