diff --git a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
index dd084ad9f..ad38b3c8f 100644
--- a/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
+++ b/tests/Composer/Test/Autoload/AutoloadGeneratorTest.php
@@ -941,8 +941,8 @@ EOF;
         $this->assertFileContentEquals(__DIR__.'/Fixtures/autoload_functions.php', $this->vendorDir.'/autoload.php');
         $this->assertFileContentEquals(__DIR__.'/Fixtures/autoload_real_functions_with_removed_include_paths_and_autolad_files.php', $this->vendorDir.'/composer/autoload_real.php');
         $this->assertFileContentEquals(__DIR__.'/Fixtures/autoload_static_functions_with_removed_include_paths_and_autolad_files.php', $this->vendorDir.'/composer/autoload_static.php');
-        $this->assertFileNotExists($this->vendorDir.'/composer/autoload_files.php');
-        $this->assertFileNotExists($this->vendorDir.'/composer/include_paths.php');
+        $this->assertFileDoesNotExist($this->vendorDir.'/composer/autoload_files.php');
+        $this->assertFileDoesNotExist($this->vendorDir.'/composer/include_paths.php');
     }
 
     public function testFilesAutoloadOrderByDependencies()
@@ -1223,7 +1223,7 @@ EOF;
 
         $this->generator->dump($this->config, $this->repository, $package, $this->im, "composer", false, '_12');
 
-        $this->assertFileNotExists($this->vendorDir."/composer/include_paths.php");
+        $this->assertFileDoesNotExist($this->vendorDir."/composer/include_paths.php");
     }
 
     public function testPreAndPostEventsAreDispatchedDuringAutoloadDump()
diff --git a/tests/Composer/Test/CacheTest.php b/tests/Composer/Test/CacheTest.php
index dffa8390a..d2a655f3a 100644
--- a/tests/Composer/Test/CacheTest.php
+++ b/tests/Composer/Test/CacheTest.php
@@ -72,7 +72,7 @@ class CacheTest extends TestCase
         $this->cache->gc(600, 1024 * 1024 * 1024);
 
         for ($i = 1; $i < 4; $i++) {
-            $this->assertFileNotExists("{$this->root}/cached.file{$i}.zip");
+            $this->assertFileDoesNotExist("{$this->root}/cached.file{$i}.zip");
         }
         $this->assertFileExists("{$this->root}/cached.file0.zip");
     }
@@ -101,7 +101,7 @@ class CacheTest extends TestCase
         $this->cache->gc(600, 1500);
 
         for ($i = 0; $i < 3; $i++) {
-            $this->assertFileNotExists("{$this->root}/cached.file{$i}.zip");
+            $this->assertFileDoesNotExist("{$this->root}/cached.file{$i}.zip");
         }
         $this->assertFileExists("{$this->root}/cached.file3.zip");
     }
diff --git a/tests/Composer/Test/Downloader/ArchiveDownloaderTest.php b/tests/Composer/Test/Downloader/ArchiveDownloaderTest.php
index 977fb6574..e2cc87bc9 100644
--- a/tests/Composer/Test/Downloader/ArchiveDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/ArchiveDownloaderTest.php
@@ -36,7 +36,7 @@ class ArchiveDownloaderTest extends TestCase
             ->will($this->returnValue('/vendor'));
 
         $first = $method->invoke($downloader, $packageMock, '/path');
-        $this->assertRegExp('#/vendor/composer/tmp-[a-z0-9]+\.js#', $first);
+        $this->assertMatchesRegularExpression('#/vendor/composer/tmp-[a-z0-9]+\.js#', $first);
         $this->assertSame($first, $method->invoke($downloader, $packageMock, '/path'));
     }
 
diff --git a/tests/Composer/Test/Downloader/FileDownloaderTest.php b/tests/Composer/Test/Downloader/FileDownloaderTest.php
index c47acf6aa..d419cb1b1 100644
--- a/tests/Composer/Test/Downloader/FileDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/FileDownloaderTest.php
@@ -98,7 +98,7 @@ class FileDownloaderTest extends TestCase
             ->with('vendor-dir')
             ->will($this->returnValue('/vendor'));
 
-        $this->assertRegExp('#/vendor/composer/tmp-[a-z0-9]+\.js#', $method->invoke($downloader, $packageMock, '/path'));
+        $this->assertMatchesRegularExpression('#/vendor/composer/tmp-[a-z0-9]+\.js#', $method->invoke($downloader, $packageMock, '/path'));
     }
 
     public function testDownloadButFileIsUnsaved()
diff --git a/tests/Composer/Test/Downloader/XzDownloaderTest.php b/tests/Composer/Test/Downloader/XzDownloaderTest.php
index 6996d67f6..1b28e707a 100644
--- a/tests/Composer/Test/Downloader/XzDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/XzDownloaderTest.php
@@ -77,7 +77,7 @@ class XzDownloaderTest extends TestCase
 
             $this->fail('Download of invalid tarball should throw an exception');
         } catch (\RuntimeException $e) {
-            $this->assertRegexp('/(File format not recognized|Unrecognized archive format)/i', $e->getMessage());
+            $this->assertMatchesRegularExpression('/(File format not recognized|Unrecognized archive format)/i', $e->getMessage());
         }
     }
 }
diff --git a/tests/Composer/Test/Installer/LibraryInstallerTest.php b/tests/Composer/Test/Installer/LibraryInstallerTest.php
index f2f2e89e6..4bf81eada 100644
--- a/tests/Composer/Test/Installer/LibraryInstallerTest.php
+++ b/tests/Composer/Test/Installer/LibraryInstallerTest.php
@@ -71,7 +71,7 @@ class LibraryInstallerTest extends TestCase
         $this->fs->removeDirectory($this->vendorDir);
 
         new LibraryInstaller($this->io, $this->composer);
-        $this->assertFileNotExists($this->vendorDir);
+        $this->assertFileDoesNotExist($this->vendorDir);
     }
 
     public function testInstallerCreationShouldNotCreateBinDirectory()
@@ -79,7 +79,7 @@ class LibraryInstallerTest extends TestCase
         $this->fs->removeDirectory($this->binDir);
 
         new LibraryInstaller($this->io, $this->composer);
-        $this->assertFileNotExists($this->binDir);
+        $this->assertFileDoesNotExist($this->binDir);
     }
 
     public function testIsInstalled()
diff --git a/tests/Composer/Test/Package/Archiver/ArchiveManagerTest.php b/tests/Composer/Test/Package/Archiver/ArchiveManagerTest.php
index 9204e6fa6..a93fe6de6 100644
--- a/tests/Composer/Test/Package/Archiver/ArchiveManagerTest.php
+++ b/tests/Composer/Test/Package/Archiver/ArchiveManagerTest.php
@@ -68,7 +68,7 @@ class ArchiveManagerTest extends ArchiverTest
         $this->assertFileExists($target);
 
         $tmppath = sys_get_temp_dir().'/composer_archiver/'.$this->manager->getPackageFilename($package);
-        $this->assertFileNotExists($tmppath);
+        $this->assertFileDoesNotExist($tmppath);
 
         unlink($target);
     }
@@ -90,7 +90,7 @@ class ArchiveManagerTest extends ArchiverTest
         $this->assertFileExists($target);
 
         $tmppath = sys_get_temp_dir().'/composer_archiver/'.$this->manager->getPackageFilename($package);
-        $this->assertFileNotExists($tmppath);
+        $this->assertFileDoesNotExist($tmppath);
 
         unlink($target);
     }
diff --git a/tests/Composer/Test/Util/ErrorHandlerTest.php b/tests/Composer/Test/Util/ErrorHandlerTest.php
index ef501542e..c7651b80a 100644
--- a/tests/Composer/Test/Util/ErrorHandlerTest.php
+++ b/tests/Composer/Test/Util/ErrorHandlerTest.php
@@ -35,7 +35,11 @@ class ErrorHandlerTest extends TestCase
      */
     public function testErrorHandlerCaptureNotice()
     {
-        $this->setExpectedException('\ErrorException', 'Undefined index: baz');
+        if (PHP_VERSION_ID >= 80000) {
+            $this->setExpectedException('\ErrorException', 'Undefined array key "baz"');
+        } else {
+            $this->setExpectedException('\ErrorException', 'Undefined index: baz');
+        }
 
         $array = array('foo' => 'bar');
         $array['baz'];
diff --git a/tests/Composer/Test/Util/FilesystemTest.php b/tests/Composer/Test/Util/FilesystemTest.php
index f3fb30278..0fb4babd8 100644
--- a/tests/Composer/Test/Util/FilesystemTest.php
+++ b/tests/Composer/Test/Util/FilesystemTest.php
@@ -168,7 +168,7 @@ class FilesystemTest extends TestCase
 
         $fs = new Filesystem;
         $this->assertTrue($fs->removeDirectoryPhp($this->workingDir));
-        $this->assertFileNotExists($this->workingDir . "/level1/level2/hello.txt");
+        $this->assertFileDoesNotExist($this->workingDir . "/level1/level2/hello.txt");
     }
 
     public function testFileSize()
@@ -247,7 +247,7 @@ class FilesystemTest extends TestCase
         $fs = new Filesystem();
         $result = $fs->unlink($symlinked);
         $this->assertTrue($result);
-        $this->assertFileNotExists($symlinked);
+        $this->assertFileDoesNotExist($symlinked);
     }
 
     /**
@@ -279,8 +279,8 @@ class FilesystemTest extends TestCase
 
         $result = $fs->removeDirectory($symlinkedTrailingSlash);
         $this->assertTrue($result);
-        $this->assertFileNotExists($symlinkedTrailingSlash);
-        $this->assertFileNotExists($symlinked);
+        $this->assertFileDoesNotExist($symlinkedTrailingSlash);
+        $this->assertFileDoesNotExist($symlinked);
     }
 
     public function testJunctions()
diff --git a/tests/Composer/Test/Util/RemoteFilesystemTest.php b/tests/Composer/Test/Util/RemoteFilesystemTest.php
index 8fe685fbc..b6b062b12 100644
--- a/tests/Composer/Test/Util/RemoteFilesystemTest.php
+++ b/tests/Composer/Test/Util/RemoteFilesystemTest.php
@@ -253,7 +253,7 @@ class RemoteFilesystemTest extends TestCase
         $res = $this->callGetOptionsForUrl($io, array('example.org', array('ssl' => array('cafile' => '/some/path/file.crt'))), array(), 'http://www.example.org');
 
         $this->assertTrue(isset($res['ssl']['ciphers']));
-        $this->assertRegExp('|!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA|', $res['ssl']['ciphers']);
+        $this->assertMatchesRegularExpression('|!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA|', $res['ssl']['ciphers']);
         $this->assertTrue($res['ssl']['verify_peer']);
         $this->assertTrue($res['ssl']['SNI_enabled']);
         $this->assertEquals(7, $res['ssl']['verify_depth']);