diff -u b/tests/src/Kernel/Processor/RenderedItemTest.php b/tests/src/Kernel/Processor/RenderedItemTest.php
--- b/tests/src/Kernel/Processor/RenderedItemTest.php
+++ b/tests/src/Kernel/Processor/RenderedItemTest.php
@@ -243,7 +243,7 @@
       // object, which contains a string (not, for example, some markup object).
       $this->assertInstanceOf('Drupal\search_api\Plugin\search_api\data_type\value\TextValueInterface', $values[0], "$type item $entity_id rendered value is properly wrapped in a text value object.");
       $field_value = $values[0]->getText();
-      $this->assertInternalType('string', $field_value, "$type item $entity_id rendered value is a string.");
+      $this->assertSame('string', gettype($field_value), "$type item $entity_id rendered value is a string.");
       $this->assertEquals(1, count($values), "$type item $entity_id rendered value is a single value.");
 
       switch ($datasource_id) {
diff -u b/tests/src/Kernel/System/CommandHelperTest.php b/tests/src/Kernel/System/CommandHelperTest.php
--- b/tests/src/Kernel/System/CommandHelperTest.php
+++ b/tests/src/Kernel/System/CommandHelperTest.php
@@ -119,7 +119,7 @@
    */
   public function testListCommand() {
     $results = $this->systemUnderTest->indexListCommand();
-    $this->assertInternalType('array', $results);
+    $this->assertSame('array', gettype($results));
     $this->assertCount(2, $results);
     $this->assertArrayHasKey('test_index', $results);
     $this->assertArrayHasKey('second_index', $results);
@@ -137,7 +137,7 @@
     $index->delete();
 
     $results = $this->systemUnderTest->indexListCommand();
-    $this->assertInternalType('array', $results);
+    $this->assertSame('array', gettype($results));
     $this->assertArrayNotHasKey('test_index', $results);
     $this->assertArrayHasKey('second_index', $results);
   }
@@ -149,7 +149,7 @@
    */
   public function testStatusCommand() {
     $results = $this->systemUnderTest->indexStatusCommand();
-    $this->assertInternalType('array', $results);
+    $this->assertSame('array', gettype($results));
     $this->assertCount(2, $results);
     $this->assertArrayHasKey('test_index', $results);
     $this->assertArrayHasKey('id', $results['test_index']);
@@ -278,7 +278,7 @@
    */
   public function testServerListCommand() {
     $result = $this->systemUnderTest->serverListCommand();
-    $this->assertInternalType('array', $result);
+    $this->assertSame('array', gettype($result));
     $this->assertCount(1, $result);
     $this->assertArrayHasKey('test_server', $result);
     $this->assertSame('test_server', $result['test_server']['id']);
@@ -291,7 +291,7 @@
     $server->save();
 
     $result = $this->systemUnderTest->serverListCommand();
-    $this->assertInternalType('array', $result);
+    $this->assertSame('array', gettype($result));
     $this->assertCount(1, $result);
     $this->assertArrayHasKey('test_server', $result);
     $this->assertSame('test_server', $result['test_server']['id']);
only in patch2:
unchanged:
--- a/tests/src/Functional/IntegrationTest.php
+++ b/tests/src/Functional/IntegrationTest.php
@@ -1045,7 +1045,7 @@ class IntegrationTest extends SearchApiBrowserTestBase {
     // Find the "Remove" link for the "body" field.
     $links = $this->xpath('//a[@data-drupal-selector=:id]', [':id' => 'edit-fields-body-remove']);
     $this->assertNotEmpty($links, 'Found "Remove" link for body field');
-    $this->assertInternalType('array', $links);
+    $this->assertSame('array', gettype($links));
     $url_target = $this->getAbsoluteUrl($links[0]->getAttribute('href'));
     $this->drupalGet($url_target);
     $this->drupalGet($this->getIndexPath('fields'));
@@ -1106,7 +1106,7 @@ class IntegrationTest extends SearchApiBrowserTestBase {
     // Find the "Remove" link for the "title" field.
     $links = $this->xpath('//a[@data-drupal-selector=:id]', [':id' => 'edit-fields-title-remove']);
     $this->assertNotEmpty($links, 'Found "Remove" link for title field');
-    $this->assertInternalType('array', $links);
+    $this->assertSame('array', gettype($links));
     $url_target = $this->getAbsoluteUrl($links[0]->getAttribute('href'));
     $this->drupalGet($url_target);
 
only in patch2:
unchanged:
--- a/tests/src/Kernel/System/SerializationTest.php
+++ b/tests/src/Kernel/System/SerializationTest.php
@@ -132,7 +132,7 @@ class SerializationTest extends KernelTestBase {
     $query = $this->createTestQuery();
     // Since Drupal's DB layer sometimes has problems with side-effects of
     // __toString(), we here try to make sure this won't happen to us.
-    $this->assertInternalType('string', (string) $query);
+    $this->assertSame('string', gettype((string) $query));
 
     $clone = clone $query;