diff --git a/.travis.yml b/.travis.yml
index 9a08353..959cd26 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,9 +5,7 @@ services:
   - mysql
 
 php:
-  - '5.6'
-  - '7.0'
-  - '7.1'
+  - '7.2'
 
 script:
     - curl -L -o reflectivedoc.php https://www.monperrus.net/martin/reflectivedoc.php.txt
@@ -33,6 +31,7 @@ script:
     # there is no need to create a post, because one activation task of wp-publications is to create a fake post
     #- $WPCLI post create --post_title=test --post_content='[wp-publications bib="sample.bib" all=true]'
     - cp bibtexbrowser.php ./wp-content/plugins/wp-publications/
+    - echo "<?php  define('BIBTEXBROWSER_USE_PROGRESSIVE_ENHANCEMENT',false);?>" > ./wp-content/plugins/wp-publications/bibtexbrowser.local.php
     - $WPCLI rest post list --slug=wp-publications-example --field=content | tee before.txt
     # do we still have the reference output? (useful for detecting changes in Wordpress or WP-CLI) (diff exits with 1 if there is a difference)
     - diff reference-output-wp-publications.txt before.txt
diff --git a/bibtexbrowser-test.php b/bibtexbrowser-test.php
index 4484dbb..d8cc0d1 100755
--- a/bibtexbrowser-test.php
+++ b/bibtexbrowser-test.php
@@ -61,7 +61,7 @@ class SimpleDisplayExt extends SimpleDisplay {
 
 class BTBTest extends PHPUnit_Framework_TestCase {
 
-    protected function setUp()
+    public function setUp():void
     {
         // resetting the default link style
         bibtexbrowser_configure('BIBTEXBROWSER_LINK_STYLE','bib2links_default');
@@ -202,7 +202,7 @@ class BTBTest extends PHPUnit_Framework_TestCase {
     $this->assertFalse(config_value('BIBTEXBROWSER_NO_DEFAULT'));
     ob_start();
     default_message();
-    $this->assertContains('Congratulations', ob_get_clean());
+    $this->assertStringContainsString('Congratulations', ob_get_clean());
   }
 
 
@@ -219,7 +219,7 @@ class BTBTest extends PHPUnit_Framework_TestCase {
     ob_start();
     $d->display();
     $data = ob_get_clean();
-    $this->assertContains('Livres', $data);
+    $this->assertStringContainsString('Livres', $data);
   }
 
 
@@ -229,7 +229,7 @@ class BTBTest extends PHPUnit_Framework_TestCase {
     $results=$btb->multisearch($q);
     $this->assertTrue(count($results) == 1);
     $entry = $results[0];
-    $this->assertContains("aKey-withSlash",$entry->toHTML());
+    $this->assertStringContainsString("aKey-withSlash",$entry->toHTML());
 
     $q=array(Q_KEY=>'aKey-withSlash');
     $results=$btb->multisearch($q);
@@ -743,7 +743,7 @@ class BTBTest extends PHPUnit_Framework_TestCase {
         $db = new BibDataBase();
         $db->update_internal("inline", $test_data);
         $entry=$db->getEntryByKey("key");
-        $this->assertContains('<a href="https://scholar.google.com/scholar?cites=1234">[citations]</a>', $entry->toHTML());
+        $this->assertStringContainsString('<a href="https://scholar.google.com/scholar?cites=1234">[citations]</a>', $entry->toHTML());
     }