diff --git a/.travis.yml b/.travis.yml
index 67ebdd4..2996e05 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -47,9 +47,9 @@ before_script:
   - php tests/_app/yii.php migrate/up --interactive=0
   - php tests/_app/yii.php migrate/up --interactive=0 --migrationPath=@yii/rbac/migrations
 
-  # enable code coverage on PHP 7.1, only one PHP version needs to generate coverage data
+  # enable code coverage on PHP 7.2, only one PHP version needs to generate coverage data
   - |
-    if [ $TRAVIS_PHP_VERSION = '7.1' ]; then
+    if [ $TRAVIS_PHP_VERSION = '7.2' ]; then
       CODECEPTION_FLAGS="--coverage-xml"
     fi
 
@@ -59,7 +59,7 @@ script:
 
 after_script:
   - |
-    if [ $TRAVIS_PHP_VERSION = '7.1' ]; then
+    if [ $TRAVIS_PHP_VERSION = '7.2' ]; then
       travis_retry wget https://scrutinizer-ci.com/ocular.phar
       php ocular.phar code-coverage:upload --format=php-clover tests/_output/coverage.xml
     fi
diff --git a/tests/functional/GdprCest.php b/tests/functional/GdprCest.php
index f6f2625..37b65f9 100644
--- a/tests/functional/GdprCest.php
+++ b/tests/functional/GdprCest.php
@@ -102,7 +102,7 @@ class GdprCest
         /** @var yii\swiftmailer\Message $message */
         $message = $I->grabLastSentEmail();
         $I->assertArrayHasKey($user->email, $message->getTo());
-        $I->assertContains(Html::encode($token->getUrl()), utf8_encode(quoted_printable_decode($message->getSwiftMessage()->toString())));
+        $I->assertStringContainsString(Html::encode($token->getUrl()), utf8_encode(quoted_printable_decode($message->getSwiftMessage()->toString())));
         $I->assertFalse($user->isConfirmed);
     }
 
@@ -123,7 +123,7 @@ class GdprCest
         /** @var yii\swiftmailer\Message $message */
         $message = $I->grabLastSentEmail();
         $I->assertArrayHasKey($user->email, $message->getTo());
-        $I->assertContains('We have generated a password for you', utf8_encode(quoted_printable_decode($message->getSwiftMessage()->toString())));
+        $I->assertStringContainsString('We have generated a password for you', utf8_encode(quoted_printable_decode($message->getSwiftMessage()->toString())));
     }
 
 
diff --git a/tests/functional/RecoveryCept.php b/tests/functional/RecoveryCept.php
index 3484aaf..ff61cfa 100644
--- a/tests/functional/RecoveryCept.php
+++ b/tests/functional/RecoveryCept.php
@@ -41,7 +41,7 @@ $token = $I->grabRecord(Token::className(), ['user_id' => $user->id, 'type' => T
 /** @var yii\swiftmailer\Message $message */
 $message = $I->grabLastSentEmail();
 $I->assertArrayHasKey($user->email, $message->getTo());
-$I->assertContains(
+$I->assertStringContainsString(
     Html::encode($token->getUrl()),
     utf8_encode(quoted_printable_decode($message->getSwiftMessage()->toString()))
 );
diff --git a/tests/functional/RegistrationCest.php b/tests/functional/RegistrationCest.php
index 903d446..e17dd9a 100644
--- a/tests/functional/RegistrationCest.php
+++ b/tests/functional/RegistrationCest.php
@@ -73,7 +73,7 @@ class RegistrationCest
         /** @var yii\swiftmailer\Message $message */
         $message = $I->grabLastSentEmail();
         $I->assertArrayHasKey($user->email, $message->getTo());
-        $I->assertContains(Html::encode($token->getUrl()), utf8_encode(quoted_printable_decode($message->getSwiftMessage()->toString())));
+        $I->assertStringContainsString(Html::encode($token->getUrl()), utf8_encode(quoted_printable_decode($message->getSwiftMessage()->toString())));
         $I->assertFalse($user->isConfirmed);
     }
 
@@ -94,7 +94,7 @@ class RegistrationCest
         /** @var yii\swiftmailer\Message $message */
         $message = $I->grabLastSentEmail();
         $I->assertArrayHasKey($user->email, $message->getTo());
-        $I->assertContains('We have generated a password for you', utf8_encode(quoted_printable_decode($message->getSwiftMessage()->toString())));
+        $I->assertStringContainsString('We have generated a password for you', utf8_encode(quoted_printable_decode($message->getSwiftMessage()->toString())));
     }
 
     protected function register(FunctionalTester $I, $email, $username = null, $password = null) {
diff --git a/tests/functional/SettingsCept.php b/tests/functional/SettingsCept.php
index 645bbb7..fb55280 100644
--- a/tests/functional/SettingsCept.php
+++ b/tests/functional/SettingsCept.php
@@ -39,7 +39,7 @@ $token = $I->grabRecord(Token::className(), ['user_id' => $user->id, 'type' => T
 /** @var yii\swiftmailer\Message $message */
 $message = $I->grabLastSentEmail();
 $I->assertArrayHasKey($user->unconfirmed_email, $message->getTo());
-$I->assertContains(Html::encode($token->getUrl()), utf8_encode(quoted_printable_decode($message->getSwiftMessage()->toString())));
+$I->assertStringContainsString(Html::encode($token->getUrl()), utf8_encode(quoted_printable_decode($message->getSwiftMessage()->toString())));
 Yii::$app->user->logout();
 
 $I->amGoingTo('log in using new email address before clicking the confirmation link');