diff --git a/phpunit.xml b/phpunit.xml
index 6430dc3..4115146 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -14,9 +14,14 @@
     testdox="true"
     timeoutForSmallTests="1" timeoutForMediumTests="10" timeoutForLargeTests="60"
     verbose="true">
-        <testsuites>
-            <testsuite name="tests">
-                <directory>tests/</directory>
-            </testsuite>
-        </testsuites>
+    <testsuites>
+        <testsuite name="tests">
+            <directory>tests/</directory>
+        </testsuite>
+    </testsuites>
+    <coverage>
+        <include>
+            <directory suffix=".php">src</directory>
+        </include>
+    </coverage>
 </phpunit>
diff --git a/tests/NodaNameSplitterTest.php b/tests/NodaNameSplitterTest.php
index c24c214..c4f2bc4 100644
--- a/tests/NodaNameSplitterTest.php
+++ b/tests/NodaNameSplitterTest.php
@@ -9,6 +9,8 @@ use PHPUnit\Framework\TestCase;
 
 /**
  * This script contains tests for the actor name splitter.
+ *
+ * @covers \NodaNameSplitter
  */
 final class NodaNameSplitterTest extends TestCase {
     /**
@@ -17,6 +19,7 @@ final class NodaNameSplitterTest extends TestCase {
      * @author Joshua Ramon Enslin <joshua@museum-digital.de>
      * @group  ValidOutput
      * @small
+     * @covers \NodaNameSplitter::givenNameFamilyNameFromString
      *
      * @return void
      */
diff --git a/tests/NodaTimeAutotranslaterTest.php b/tests/NodaTimeAutotranslaterTest.php
index 0508798..d8bfda9 100644
--- a/tests/NodaTimeAutotranslaterTest.php
+++ b/tests/NodaTimeAutotranslaterTest.php
@@ -9,6 +9,8 @@ use PHPUnit\Framework\TestCase;
 
 /**
  * This script contains tests for the automatic translation class for time names.
+ *
+ * @covers \NodaTimeAutotranslater
  */
 final class NodaTimeAutotranslaterTest extends TestCase {
     /**
diff --git a/tests/NodaTimeSplitterTest.php b/tests/NodaTimeSplitterTest.php
index 67324a7..357e65c 100644
--- a/tests/NodaTimeSplitterTest.php
+++ b/tests/NodaTimeSplitterTest.php
@@ -9,6 +9,8 @@ use PHPUnit\Framework\TestCase;
 
 /**
  * This script contains tests for the time name splitter.
+ *
+ * @covers \NodaTimeSplitter
  */
 final class NodaTimeSplitterTest extends TestCase {
     /**
diff --git a/tests/NodaUncertaintyHelperTest.php b/tests/NodaUncertaintyHelperTest.php
index 15cbf91..b7c3ae5 100644
--- a/tests/NodaUncertaintyHelperTest.php
+++ b/tests/NodaUncertaintyHelperTest.php
@@ -9,6 +9,8 @@ use PHPUnit\Framework\TestCase;
 
 /**
  * This script contains tests for the uncertainty helper.
+ *
+ * @covers \NodaUncertaintyHelper
  */
 final class NodaUncertaintyHelperTest extends TestCase {
     /**
diff --git a/tests/NodaValidationHelperTest.php b/tests/NodaValidationHelperTest.php
index 90c37bc..41bfe66 100644
--- a/tests/NodaValidationHelperTest.php
+++ b/tests/NodaValidationHelperTest.php
@@ -9,8 +9,24 @@ use PHPUnit\Framework\TestCase;
 
 /**
  * This script contains tests for the validation of single field contents.
+ *
+ * @covers \NodaValidationHelper
  */
 final class NodaValidationHelperTest extends TestCase {
+    /**
+     * Test that a specific error is thrown if no description for actors is provided.
+     *
+     * @small
+     *
+     * @return void
+     */
+    public function testActorDescriptionValidationFailsOnEmptyInput():void {
+
+        $this->expectException(MDInvalidEmptyInputException::class);
+        NodaValidationHelper::validateActorDescription("");
+
+    }
+
     /**
      * Test successfully refusing too short actor descriptions.
      *
diff --git a/tests/NodaWikidataFetcherTest.php b/tests/NodaWikidataFetcherTest.php
index bfdc1f7..853b652 100644
--- a/tests/NodaWikidataFetcherTest.php
+++ b/tests/NodaWikidataFetcherTest.php
@@ -9,6 +9,8 @@ use PHPUnit\Framework\TestCase;
 
 /**
  * This script contains tests for the Wikidata fetcher.
+ *
+ * @covers \NodaWikidataFetcher
  */
 final class NodaWikidataFetcherTest extends TestCase {
     /**