diff --git a/pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/port/out/RunLockUnavailableException.java b/pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/port/out/RunLockUnavailableException.java
index 588bf8d..4a34c19 100644
--- a/pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/port/out/RunLockUnavailableException.java
+++ b/pdf-umbenenner-application/src/main/java/de/gecheckt/pdf/umbenenner/application/port/out/RunLockUnavailableException.java
@@ -14,7 +14,9 @@ package de.gecheckt.pdf.umbenenner.application.port.out;
  */
 public class RunLockUnavailableException extends RuntimeException {
 
-    /**
+    private static final long serialVersionUID = -6696023481584876000L;
+
+	/**
      * Creates a new RunLockUnavailableException with the given message.
      *
      * @param message description of why the lock could not be acquired
diff --git a/pdf-umbenenner-domain/src/test/java/de/gecheckt/pdf/umbenenner/domain/model/ProcessingStatusTest.java b/pdf-umbenenner-domain/src/test/java/de/gecheckt/pdf/umbenenner/domain/model/ProcessingStatusTest.java
index 8c690c4..dc0f510 100644
--- a/pdf-umbenenner-domain/src/test/java/de/gecheckt/pdf/umbenenner/domain/model/ProcessingStatusTest.java
+++ b/pdf-umbenenner-domain/src/test/java/de/gecheckt/pdf/umbenenner/domain/model/ProcessingStatusTest.java
@@ -62,8 +62,7 @@ class ProcessingStatusTest {
     @Test
     void statusEquality_worksByReference() {
         // Enums have identity-based equality
-        assertTrue(ProcessingStatus.SUCCESS == ProcessingStatus.SUCCESS);
-        assertFalse(ProcessingStatus.SUCCESS == ProcessingStatus.FAILED_FINAL);
+        assertNotSame(ProcessingStatus.SUCCESS, ProcessingStatus.FAILED_FINAL);
     }
 
     @Test
diff --git a/pdf-umbenenner-domain/src/test/java/de/gecheckt/pdf/umbenenner/domain/model/RunIdTest.java b/pdf-umbenenner-domain/src/test/java/de/gecheckt/pdf/umbenenner/domain/model/RunIdTest.java
index 06bcf7b..8ab856c 100644
--- a/pdf-umbenenner-domain/src/test/java/de/gecheckt/pdf/umbenenner/domain/model/RunIdTest.java
+++ b/pdf-umbenenner-domain/src/test/java/de/gecheckt/pdf/umbenenner/domain/model/RunIdTest.java
@@ -61,15 +61,13 @@ class RunIdTest {
     @Test
     void equals_returnsFalseWhenComparedWithNull() {
         RunId runId = new RunId("test-id");
-        assertNotEquals(runId, null);
-        assertFalse(runId.equals(null));
+        assertNotEquals(null, runId);
     }
 
     @Test
     void equals_returnsFalseWhenComparedWithDifferentType() {
         RunId runId = new RunId("test-id");
-        assertNotEquals(runId, "test-id");
-        assertFalse(runId.equals("test-id"));
+        assertNotEquals("test-id", runId);
     }
 
     @Test