diff --git a/core/modules/image/src/Tests/ImageFieldDisplayTest.php b/core/modules/image/src/Tests/ImageFieldDisplayTest.php
index 780abd9..206e079 100644
--- a/core/modules/image/src/Tests/ImageFieldDisplayTest.php
+++ b/core/modules/image/src/Tests/ImageFieldDisplayTest.php
@@ -18,6 +18,16 @@
 class ImageFieldDisplayTest extends ImageFieldTestBase {
 
   /**
+   * Indicates that headers should be dumped if verbose output is enabled.
+   *
+   * Headers are dumped to verbose by drupalGet(), drupalHead(), and
+   * drupalPostForm().
+   *
+   * @var bool
+   */
+  protected $dumpHeaders = TRUE;
+
+  /**
    * Modules to enable.
    *
    * @var array