diff --git a/backup/util/settings/tests/settings_test.php b/backup/util/settings/tests/settings_test.php
index 289f30fec7f..1f512d563a9 100644
--- a/backup/util/settings/tests/settings_test.php
+++ b/backup/util/settings/tests/settings_test.php
@@ -128,7 +128,7 @@ class backp_settings_testcase extends basic_testcase {
             $this->assertEquals($e->errorcode, 'incorrect_object_passed');
         } catch (TypeError $e) {
             // On PHP7+ we get a TypeError raised, lets check we've the right error.
-            $this->assertMatchesRegularExpression('/must be an instance of backup_setting_ui/', $e->getMessage());
+            $this->assertMatchesRegularExpression('/must be (of type|an instance of) backup_setting_ui/', $e->getMessage());
         }
         restore_error_handler();
 
@@ -145,7 +145,7 @@ class backp_settings_testcase extends basic_testcase {
             $this->assertEquals($e->errorcode, 'incorrect_object_passed');
         } catch (TypeError $e) {
             // On PHP7+ we get a TypeError raised, lets check we've the right error.
-            $this->assertMatchesRegularExpression('/must be an instance of backup_setting_ui/', $e->getMessage());
+            $this->assertMatchesRegularExpression('/must be (of type|an instance of) backup_setting_ui/', $e->getMessage());
         }
         restore_error_handler();
 
@@ -354,7 +354,7 @@ class backp_settings_testcase extends basic_testcase {
             $this->assertEquals($e->errorcode, 'incorrect_object_passed');
         } catch (TypeError $e) {
             // On PHP7+ we get a TypeError raised, lets check we've the right error.
-            $this->assertMatchesRegularExpression('/must be an instance of base_setting/', $e->getMessage());
+            $this->assertMatchesRegularExpression('/must be (an instance of|of type) base_setting/', $e->getMessage());
         }
         restore_error_handler();
 
diff --git a/lib/phpunit/tests/basic_test.php b/lib/phpunit/tests/basic_test.php
index df989ee6a77..53f25936142 100644
--- a/lib/phpunit/tests/basic_test.php
+++ b/lib/phpunit/tests/basic_test.php
@@ -96,7 +96,6 @@ class core_phpunit_basic_testcase extends basic_testcase {
         $this->assertEquals(1, '1');
         $this->assertEquals(null, '');
 
-        $this->assertNotEquals(1, '1 ');
         $this->assertNotEquals(0, '');
         $this->assertNotEquals(null, '0');
         $this->assertNotEquals(array(), '');
diff --git a/lib/tests/encryption_test.php b/lib/tests/encryption_test.php
index 60094f02a8b..81602d1472e 100644
--- a/lib/tests/encryption_test.php
+++ b/lib/tests/encryption_test.php
@@ -216,7 +216,7 @@ class encryption_testcase extends \basic_testcase {
 
         switch ($method) {
             case encryption::METHOD_SODIUM:
-                $this->expectExceptionMessage('key size should be');
+                $this->expectExceptionMessageMatches('/(should|must) be SODIUM_CRYPTO_SECRETBOX_KEYBYTES bytes/');
                 break;
 
             case encryption::METHOD_OPENSSL:
diff --git a/lib/tests/event_test.php b/lib/tests/event_test.php
index 476eaf66efb..208482482c9 100644
--- a/lib/tests/event_test.php
+++ b/lib/tests/event_test.php
@@ -857,7 +857,11 @@ class core_event_testcase extends advanced_testcase {
         // all that was done is to move the annotation (deprecated) to
         // explicit expectation. Still try commenting it out and you'll see
         // the notice.
-        $this->expectNotice();
+        if (PHP_VERSION_ID >= 80000) {
+            $this->expectWarning();
+        } else {
+            $this->expectNotice();
+        }
         $event = \core_tests\event\context_used_in_event::create(array('other' => array('sample' => 1, 'xx' => 10)));
         $this->assertEventContextNotUsed($event);
 
diff --git a/lib/tests/moodlelib_test.php b/lib/tests/moodlelib_test.php
index bc8315c78ff..34f2f1c0a7d 100644
--- a/lib/tests/moodlelib_test.php
+++ b/lib/tests/moodlelib_test.php
@@ -2302,7 +2302,11 @@ EOF;
     public function test_get_string_limitation() {
         // This is one of the limitations to the lang_string class. It can't be
         // used as a key.
-        $this->expectWarning();
+        if (PHP_VERSION_ID >= 80000) {
+            $this->expectException(TypeError::class);
+        } else {
+            $this->expectWarning();
+        }
         $array = array(get_string('yes', null, null, true) => 'yes');
     }
 
diff --git a/mod/forum/tests/mail_test.php b/mod/forum/tests/mail_test.php
index 8f6725801c6..c9d0247b8b8 100644
--- a/mod/forum/tests/mail_test.php
+++ b/mod/forum/tests/mail_test.php
@@ -1016,8 +1016,8 @@ class mod_forum_mail_testcase extends advanced_testcase {
                     'contents' => array(
                         '~{$a',
                         '~&(amp|lt|gt|quot|\#039);(?!course)',
-                        'Attachment example.txt:' . PHP_EOL .
-                            'https://www.example.com/moodle/pluginfile.php/\d*/mod_forum/attachment/\d*/example.txt' . PHP_EOL,
+                        'Attachment example.txt:' . '\r*\n' .
+                            'https://www.example.com/moodle/pluginfile.php/\d*/mod_forum/attachment/\d*/example.txt' . '\r*\n',
                         'Hello Moodle', 'Moodle Forum', 'Welcome.*Moodle', 'Love Moodle', '1\d1'
                     ),
                 ),
@@ -1075,12 +1075,12 @@ class mod_forum_mail_testcase extends advanced_testcase {
         $newcase['expectations'][0]['contents'] = array(
             '~{$a',
             '~&(amp|lt|gt|quot|\#039);(?!course)',
-            'Attachment example.txt:' . PHP_EOL .
-            'https://www.example.com/moodle/pluginfile.php/\d*/mod_forum/attachment/\d*/example.txt' .  PHP_EOL ,
+            'Attachment example.txt:' . '\r*\n' .
+            'https://www.example.com/moodle/pluginfile.php/\d*/mod_forum/attachment/\d*/example.txt' .  '\r*\n' ,
             'Text and image', 'Moodle Forum',
-            'Welcome to Moodle, *' . PHP_EOL . '.*'
+            'Welcome to Moodle, *' . '\r*\n' . '.*'
                 .'https://www.example.com/moodle/pluginfile.php/\d+/mod_forum/post/\d+/'
-                .'Screen%20Shot%202016-03-22%20at%205\.54\.36%20AM%20%281%29\.png *' . PHP_EOL . '.*!',
+                .'Screen%20Shot%202016-03-22%20at%205\.54\.36%20AM%20%281%29\.png *' . '\r*\n' . '.*!',
             'Love Moodle', '1\d1');
         $textcases['Text mail with text+image message i.e. @@PLUGINFILE@@ token handling'] = array('data' => $newcase);