diff --git a/tests/InterfaceImplementationTest.php b/tests/InterfaceImplementationTest.php
index c565140..7d25de8 100644
--- a/tests/InterfaceImplementationTest.php
+++ b/tests/InterfaceImplementationTest.php
@@ -41,11 +41,6 @@ final class InterfaceImplementationTest extends TestCase {
     /**
      * Test all concordance lists for their implementation of MDImporterConcordanceListInterface.
      *
-     * @author Joshua Ramon Enslin <joshua@museum-digital.de>
-     * @group  ValidOutput
-     * @group  HTMLOutput
-     * @group  SafeForProduction
-     *
      * @return void
      */
     public function testListInterfaceIsImplemented():void {
@@ -61,4 +56,19 @@ final class InterfaceImplementationTest extends TestCase {
         }
 
     }
+
+    /**
+     * Ensure all tests throw the MDImporterMissingConcordance exception, if
+     * a new value is encountered.
+     *
+     * @return void
+     */
+    public function testMDImporterMissingConcordanceIsThrownForNewValues():void {
+
+        foreach ($this->_lists as $list) {
+            $this->expectException(MDImporterMissingConcordance::class);
+            (new $list)::getConcordanceTarget("ThisInputShouldNotExist");
+        }
+
+    }
 }