diff --git a/tests/legacy/ApiTest.php b/tests/legacy/ApiTest.php
index 6dd4066898..837b7409b0 100644
--- a/tests/legacy/ApiTest.php
+++ b/tests/legacy/ApiTest.php
@@ -189,7 +189,7 @@ class ApiTest extends FixtureTest
 	private function assertXml($result = '', $root_element = '')
 	{
 		self::assertStringStartsWith('<?xml version="1.0"?>', $result);
-		self::assertContains('<' . $root_element, $result);
+		self::assertStringContainsString('<' . $root_element, $result);
 		// We could probably do more checks here.
 	}
 
@@ -1505,7 +1505,7 @@ class ApiTest extends FixtureTest
 		$result             = api_search('json');
 		foreach ($result['status'] as $status) {
 			self::assertStatus($status);
-			self::assertContains('reply', $status['text'], '', true);
+			self::assertStringContainsStringIgnoringCase('reply', $status['text'], '', true);
 		}
 	}
 
@@ -1521,7 +1521,7 @@ class ApiTest extends FixtureTest
 		$result            = api_search('json');
 		foreach ($result['status'] as $status) {
 			self::assertStatus($status);
-			self::assertContains('reply', $status['text'], '', true);
+			self::assertStringContainsStringIgnoringCase('reply', $status['text'], '', true);
 		}
 	}
 
@@ -1537,7 +1537,7 @@ class ApiTest extends FixtureTest
 		$result          = api_search('json');
 		foreach ($result['status'] as $status) {
 			self::assertStatus($status);
-			self::assertContains('reply', $status['text'], '', true);
+			self::assertStringContainsStringIgnoringCase('reply', $status['text'], '', true);
 		}
 	}
 
@@ -1551,7 +1551,7 @@ class ApiTest extends FixtureTest
 		$result        = api_search('json');
 		foreach ($result['status'] as $status) {
 			self::assertStatus($status);
-			self::assertContains('#friendica', $status['text'], '', true);
+			self::assertStringContainsStringIgnoringCase('#friendica', $status['text'], '', true);
 		}
 	}
 
@@ -2874,7 +2874,7 @@ class ApiTest extends FixtureTest
 		$_POST['text']        = 'message_text';
 		$_POST['screen_name'] = $this->friendUser['nick'];
 		$result               = api_direct_messages_new('json');
-		self::assertContains('message_text', $result['direct_message']['text']);
+		self::assertStringContainsString('message_text', $result['direct_message']['text']);
 		self::assertEquals('selfcontact', $result['direct_message']['sender_screen_name']);
 		self::assertEquals(1, $result['direct_message']['friendica_seen']);
 	}
@@ -2891,8 +2891,8 @@ class ApiTest extends FixtureTest
 		$_POST['screen_name'] = $this->friendUser['nick'];
 		$_REQUEST['title']    = 'message_title';
 		$result               = api_direct_messages_new('json');
-		self::assertContains('message_text', $result['direct_message']['text']);
-		self::assertContains('message_title', $result['direct_message']['text']);
+		self::assertStringContainsString('message_text', $result['direct_message']['text']);
+		self::assertStringContainsString('message_title', $result['direct_message']['text']);
 		self::assertEquals('selfcontact', $result['direct_message']['sender_screen_name']);
 		self::assertEquals(1, $result['direct_message']['friendica_seen']);
 	}
diff --git a/tests/src/Util/EMailerTest.php b/tests/src/Util/EMailerTest.php
index 3b1c3cc1f3..7f96e010a5 100644
--- a/tests/src/Util/EMailerTest.php
+++ b/tests/src/Util/EMailerTest.php
@@ -78,16 +78,16 @@ class EMailerTest extends MockedTest
 
 		self::assertTrue($emailer->send($testEmail));
 
-		self::assertContains("X-Friendica-Host: friendica.local", EmailerSpy::$MAIL_DATA['headers']);
-		self::assertContains("X-Friendica-Platform: Friendica", EmailerSpy::$MAIL_DATA['headers']);
-		self::assertContains("List-ID: <notification.friendica.local>", EmailerSpy::$MAIL_DATA['headers']);
-		self::assertContains("List-Archive: <http://friendica.local/notifications/system>", EmailerSpy::$MAIL_DATA['headers']);
-		self::assertContains("Reply-To: Sender <sender@friendica.local>", EmailerSpy::$MAIL_DATA['headers']);
-		self::assertContains("MIME-Version: 1.0", EmailerSpy::$MAIL_DATA['headers']);
+		self::assertStringContainsString("X-Friendica-Host: friendica.local", EmailerSpy::$MAIL_DATA['headers']);
+		self::assertStringContainsString("X-Friendica-Platform: Friendica", EmailerSpy::$MAIL_DATA['headers']);
+		self::assertStringContainsString("List-ID: <notification.friendica.local>", EmailerSpy::$MAIL_DATA['headers']);
+		self::assertStringContainsString("List-Archive: <http://friendica.local/notifications/system>", EmailerSpy::$MAIL_DATA['headers']);
+		self::assertStringContainsString("Reply-To: Sender <sender@friendica.local>", EmailerSpy::$MAIL_DATA['headers']);
+		self::assertStringContainsString("MIME-Version: 1.0", EmailerSpy::$MAIL_DATA['headers']);
 		// Base64 "Test Text"
-		self::assertContains(chunk_split(base64_encode('Test Text')), EmailerSpy::$MAIL_DATA['body']);
+		self::assertStringContainsString(chunk_split(base64_encode('Test Text')), EmailerSpy::$MAIL_DATA['body']);
 		// Base64 "Test Message<b>Bold</b>"
-		self::assertContains(chunk_split(base64_encode("Test Message<b>Bold</b>")), EmailerSpy::$MAIL_DATA['body']);
+		self::assertStringContainsString(chunk_split(base64_encode("Test Message<b>Bold</b>")), EmailerSpy::$MAIL_DATA['body']);
 		self::assertEquals("Test Subject", EmailerSpy::$MAIL_DATA['subject']);
 		self::assertEquals("recipient@friendica.local", EmailerSpy::$MAIL_DATA['to']);
 		self::assertEquals("-f sender@friendica.local", EmailerSpy::$MAIL_DATA['parameters']);
diff --git a/tests/src/Util/Logger/AbstractLoggerTest.php b/tests/src/Util/Logger/AbstractLoggerTest.php
index 44e210b9ca..d008f4dc42 100644
--- a/tests/src/Util/Logger/AbstractLoggerTest.php
+++ b/tests/src/Util/Logger/AbstractLoggerTest.php
@@ -106,8 +106,8 @@ abstract class AbstractLoggerTest extends MockedTest
 		$logger->emergency('A {psr} test', ['psr' => 'working']);
 		$logger->alert('An {array} test', ['array' => ['it', 'is', 'working']]);
 		$text = $this->getContent();
-		self::assertContains('A working test', $text);
-		self::assertContains('An ["it","is","working"] test', $text);
+		self::assertStringContainsString('A working test', $text);
+		self::assertStringContainsString('An ["it","is","working"] test', $text);
 	}
 
 	/**
@@ -119,9 +119,9 @@ abstract class AbstractLoggerTest extends MockedTest
 		$logger->emergency('A test');
 
 		$text = $this->getContent();
-		self::assertContains('"file":"' . self::FILE . '"', $text);
-		self::assertContains('"line":' . self::LINE, $text);
-		self::assertContains('"function":"' . self::FUNC . '"', $text);
+		self::assertStringContainsString('"file":"' . self::FILE . '"', $text);
+		self::assertStringContainsString('"line":' . self::LINE, $text);
+		self::assertStringContainsString('"function":"' . self::FUNC . '"', $text);
 	}
 
 	/**
@@ -157,7 +157,7 @@ abstract class AbstractLoggerTest extends MockedTest
 
 		self::assertLogline($text);
 
-		self::assertContains(@json_encode($context), $text);
+		self::assertStringContainsString(@json_encode($context), $text);
 	}
 
 	/**
@@ -176,7 +176,7 @@ abstract class AbstractLoggerTest extends MockedTest
 
 		self::assertLogline($text);
 
-		self::assertContains(@json_encode($assertion), $this->getContent());
+		self::assertStringContainsString(@json_encode($assertion), $this->getContent());
 	}
 
 	public function testNoObjectHandling()
@@ -187,6 +187,6 @@ abstract class AbstractLoggerTest extends MockedTest
 
 		self::assertLogline($text);
 
-		self::assertContains('test', $this->getContent());
+		self::assertStringContainsString('test', $this->getContent());
 	}
 }