diff --git a/tests/src/OneLogin/Saml2/MetadataTest.php b/tests/src/OneLogin/Saml2/MetadataTest.php
index 3a93e3eb..290ff9ff 100644
--- a/tests/src/OneLogin/Saml2/MetadataTest.php
+++ b/tests/src/OneLogin/Saml2/MetadataTest.php
@@ -165,8 +165,9 @@ public function testSignMetadata()
         try {
             $signedMetadata2 = Metadata::signMetadata('', $key, $cert);
             $this->fail('Exception was not raised');
-        } catch (\Error $e) {
-            $this->assertStringContainsString('Argument #1 ($source) must not be empty', $e->getMessage());
+        } catch (\Error | \Exception $e) {
+            $expectedErrors = array('DOMDocument::loadXML(): Argument #1 ($source) must not be empty', 'DOMDocument::loadXML(): Empty string supplied as input');
+            $this->assertTrue(in_array($e->getMessage(), $expectedErrors));
         }
     }
 
@@ -261,8 +262,9 @@ public function testAddX509KeyDescriptors()
         try {
             $signedMetadata2 = Metadata::addX509KeyDescriptors('', $cert);
             $this->fail('Exception was not raised');
-        } catch (\Error $e) {
-            $this->assertStringContainsString('Argument #1 ($source) must not be empty', $e->getMessage());
+        } catch (\Error | \Exception $e) {
+            $expectedErrors = array('DOMDocument::loadXML(): Argument #1 ($source) must not be empty', 'Error parsing metadata. DOMDocument::loadXML(): Empty string supplied as input');
+            $this->assertTrue(in_array($e->getMessage(), $expectedErrors));
         }
 
         libxml_use_internal_errors(true);
diff --git a/tests/src/OneLogin/Saml2/SettingsTest.php b/tests/src/OneLogin/Saml2/SettingsTest.php
index 87708629..ca0ed7c4 100644
--- a/tests/src/OneLogin/Saml2/SettingsTest.php
+++ b/tests/src/OneLogin/Saml2/SettingsTest.php
@@ -831,8 +831,9 @@ public function testValidateMetadataNoXML()
         try {
             $errors = $settings->validateMetadata($metadata);
             $this->fail('Exception was not raised');
-        } catch (\Error $e) {
-            $this->assertStringContainsString('Argument #1 ($source) must not be empty', $e->getMessage());
+        } catch (\Error | \Exception $e) {
+            $expectedErrors = array('DOMDocument::loadXML(): Argument #1 ($source) must not be empty', 'DOMDocument::loadXML(): Empty string supplied as input');
+            $this->assertTrue(in_array($e->getMessage(), $expectedErrors));
         }
 
         $metadata = '<no xml>';