tests/src/Functional/JsonApiExtrasFunctionalTest.php | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tests/src/Functional/JsonApiExtrasFunctionalTest.php b/tests/src/Functional/JsonApiExtrasFunctionalTest.php
index a6cc200..be6cf82 100644
--- a/tests/src/Functional/JsonApiExtrasFunctionalTest.php
+++ b/tests/src/Functional/JsonApiExtrasFunctionalTest.php
@@ -30,6 +30,11 @@ class JsonApiExtrasFunctionalTest extends JsonApiFunctionalTestBase {
    * {@inheritdoc}
    */
   protected function setUp() {
+    // Check that the e0ipso/shaper library is available.
+    if (!class_exists("\\Shaper\\DataAdaptor\\DataAdaptorBase")) {
+      $this->fail('The e0ipso/shaper library is missing. You can install it with `composer require e0ipso/shaper`.');
+    }
+
     parent::setUp();
     // Add vocabs field to the tags.
     $this->createEntityReferenceField(