diff --git a/pom.xml b/pom.xml
index 59f73f54..d63689eb 100644
--- a/pom.xml
+++ b/pom.xml
@@ -4,7 +4,7 @@
     <groupId>com.github.libgraviton</groupId>
     <artifactId>worker-base</artifactId>
     <packaging>jar</packaging>
-    <version>0.24.0</version>
+    <version>0.25.0</version>
     <name>Graviton Worker Base Library</name>
     <url>https://github.com/libgraviton/graviton-worker-base-java</url>
     <inceptionYear>2015</inceptionYear>
@@ -62,7 +62,7 @@
         <dependency>
             <groupId>com.github.libgraviton</groupId>
             <artifactId>gdk-core</artifactId>
-            <version>0.3.4</version>
+            <version>0.4.0</version>
         </dependency>
         <dependency>
             <groupId>com.github.libgraviton</groupId>
diff --git a/src/main/java/com/github/libgraviton/workerbase/FileWorkerAbstract.java b/src/main/java/com/github/libgraviton/workerbase/FileWorkerAbstract.java
index 9415d997..ba675665 100644
--- a/src/main/java/com/github/libgraviton/workerbase/FileWorkerAbstract.java
+++ b/src/main/java/com/github/libgraviton/workerbase/FileWorkerAbstract.java
@@ -1,8 +1,3 @@
-/**
- * abstract base class for file workers providing convenience.
- * it extends WorkerAbstract but provides more functions for /file api handling
- */
-
 package com.github.libgraviton.workerbase;
 
 import com.github.libgraviton.gdk.GravitonFileEndpoint;
@@ -33,7 +28,7 @@ public abstract class FileWorkerAbstract extends WorkerAbstract {
 
     protected File gravitonFile;
 
-    protected GravitonFileEndpoint fileEndpoint = initFileEndpoint();
+    protected GravitonFileEndpoint fileEndpoint;
 
     public boolean shouldHandleRequest(QueueEvent queueEvent) throws WorkerException, GravitonCommunicationException {
         // reset gravitonFile, to make sure we have no cached values that will interfere.
@@ -51,6 +46,12 @@ public boolean shouldHandleRequest(QueueEvent queueEvent) throws WorkerException
         return actionOfInterestPresent;
     }
 
+    @Override
+    public void onStartUp() throws WorkerException {
+        super.onStartUp();
+        fileEndpoint = initFileEndpoint();
+    }
+
     /**
      * Get required action of interest for worker.
      *
diff --git a/src/main/java/com/github/libgraviton/workerbase/GravitonAuthApi.java b/src/main/java/com/github/libgraviton/workerbase/GravitonAuthApi.java
index 11dcd574..470d6512 100644
--- a/src/main/java/com/github/libgraviton/workerbase/GravitonAuthApi.java
+++ b/src/main/java/com/github/libgraviton/workerbase/GravitonAuthApi.java
@@ -2,9 +2,7 @@
 
 import com.github.libgraviton.gdk.GravitonApi;
 import com.github.libgraviton.gdk.api.header.HeaderBag;
-import com.github.libgraviton.gdk.util.PropertiesLoader;
 
-import java.io.IOException;
 import java.util.Properties;
 
 /**
@@ -16,30 +14,22 @@
  */
 public class GravitonAuthApi extends GravitonApi {
 
-    protected Properties properties;
+    protected String authHeaderName;
+    protected String authHeaderValue;
 
-    @Override
-    protected HeaderBag getDefaultHeaders() {
-        String authHeaderValue = properties.getProperty("graviton.authentication.prefix.username")
+
+    public GravitonAuthApi(Properties properties) {
+        super();
+        this.authHeaderValue = properties.getProperty("graviton.authentication.prefix.username")
                 .concat(properties.getProperty("graviton.workerId"));
-        String authHeaderName = properties.getProperty("graviton.authentication.header.name");
+        this.authHeaderName = properties.getProperty("graviton.authentication.header.name");
+    }
 
+    @Override
+    protected HeaderBag.Builder getDefaultHeaders() {
         return new HeaderBag.Builder()
                 .set("Content-Type", "application/json")
                 .set("Accept", "application/json")
-                .set(authHeaderName, authHeaderValue)
-                .build();
-    }
-
-
-    // TODO remove the setup override as soon as properties is no longer private in GravitonApi
-    @Override
-    protected void setup() {
-        try {
-            this.properties = PropertiesLoader.load();
-        } catch (IOException e) {
-            throw new IllegalStateException("Unable to load properties files.", e);
-        }
-        super.setup();
+                .set(authHeaderName, authHeaderValue);
     }
 }
diff --git a/src/main/java/com/github/libgraviton/workerbase/WorkerAbstract.java b/src/main/java/com/github/libgraviton/workerbase/WorkerAbstract.java
index 9bda70c8..8ba5f870 100644
--- a/src/main/java/com/github/libgraviton/workerbase/WorkerAbstract.java
+++ b/src/main/java/com/github/libgraviton/workerbase/WorkerAbstract.java
@@ -1,7 +1,3 @@
-/**
- * abstract base class for workers providing convenience
- */
-
 package com.github.libgraviton.workerbase;
 
 import com.github.libgraviton.gdk.GravitonApi;
@@ -50,7 +46,7 @@ public abstract class WorkerAbstract {
 
     protected MessageAcknowledger acknowledger;
 
-    protected GravitonApi gravitonApi = initGravitonApi();
+    protected GravitonApi gravitonApi;
 
     public Properties getProperties() {
         return properties;
@@ -94,6 +90,7 @@ public Boolean getRegistered() {
      */
     public final void initialize(Properties properties) throws WorkerException, GravitonCommunicationException  {
         this.properties = properties;
+        this.gravitonApi = initGravitonApi();
         workerId = properties.getProperty("graviton.workerId");
 
         if (shouldAutoRegister()) {
@@ -282,6 +279,6 @@ public QueueManager getQueueManager() {
     }
 
     protected GravitonApi initGravitonApi() {
-        return new GravitonAuthApi();
+        return new GravitonAuthApi(properties);
     }
 }
diff --git a/src/main/java/com/github/libgraviton/workerbase/logging/TruncatedMessageConverter.java b/src/main/java/com/github/libgraviton/workerbase/logging/TruncatedMessageConverter.java
index 96859380..5063a913 100644
--- a/src/main/java/com/github/libgraviton/workerbase/logging/TruncatedMessageConverter.java
+++ b/src/main/java/com/github/libgraviton/workerbase/logging/TruncatedMessageConverter.java
@@ -33,6 +33,8 @@ public String convert(ILoggingEvent event) {
 
     /**
      * For some reason getOptionList() is protected. With getOptions() it's exposed and testable.
+     *
+     * @return options list
      */
     public List<String> getOptions() {
         return getOptionList();
diff --git a/src/test/java/com/github/libgraviton/workerbase/GravitonAuthApiTest.java b/src/test/java/com/github/libgraviton/workerbase/GravitonAuthApiTest.java
index 9e7d4137..a0857390 100644
--- a/src/test/java/com/github/libgraviton/workerbase/GravitonAuthApiTest.java
+++ b/src/test/java/com/github/libgraviton/workerbase/GravitonAuthApiTest.java
@@ -2,6 +2,7 @@
 
 import com.github.libgraviton.gdk.api.header.Header;
 import com.github.libgraviton.gdk.api.header.HeaderBag;
+import com.github.libgraviton.workerbase.helper.PropertiesLoader;
 import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
@@ -9,9 +10,9 @@
 public class GravitonAuthApiTest {
 
     @Test
-    public void testGetDefaultHeader() {
-        GravitonAuthApi gravitonApi = new GravitonAuthApi();
-        HeaderBag headers = gravitonApi.getDefaultHeaders();
+    public void testGetDefaultHeader() throws Exception {
+        GravitonAuthApi gravitonApi = new GravitonAuthApi(PropertiesLoader.load());
+        HeaderBag headers = gravitonApi.getDefaultHeaders().build();
         assertEquals(3, headers.all().size());
 
         Header header = headers.get("x-graviton-authentication");
diff --git a/src/test/java/com/github/libgraviton/workerbase/WorkerBaseTestCase.java b/src/test/java/com/github/libgraviton/workerbase/WorkerBaseTestCase.java
index 58584b02..b53307b2 100644
--- a/src/test/java/com/github/libgraviton/workerbase/WorkerBaseTestCase.java
+++ b/src/test/java/com/github/libgraviton/workerbase/WorkerBaseTestCase.java
@@ -1,7 +1,6 @@
 package com.github.libgraviton.workerbase;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
-import com.github.libgraviton.gdk.GravitonApi;
 import com.github.libgraviton.gdk.api.Response;
 import com.github.libgraviton.gdk.data.GravitonBase;
 import com.github.libgraviton.gdk.serialization.mapper.GravitonObjectMapper;
diff --git a/src/test/java/com/github/libgraviton/workerbase/lib/TestFileWorker.java b/src/test/java/com/github/libgraviton/workerbase/lib/TestFileWorker.java
index 1e044431..24c6d9f9 100644
--- a/src/test/java/com/github/libgraviton/workerbase/lib/TestFileWorker.java
+++ b/src/test/java/com/github/libgraviton/workerbase/lib/TestFileWorker.java
@@ -58,6 +58,6 @@ public List<String> getActionsOfInterest(QueueEvent queueEvent) {
     }
 
     protected GravitonApi initGravitonApi() {
-        return null;
+        return gravitonApi;
     }
 }
diff --git a/src/test/java/com/github/libgraviton/workerbase/lib/TestWorker.java b/src/test/java/com/github/libgraviton/workerbase/lib/TestWorker.java
index 1ec4235f..4b91d39e 100644
--- a/src/test/java/com/github/libgraviton/workerbase/lib/TestWorker.java
+++ b/src/test/java/com/github/libgraviton/workerbase/lib/TestWorker.java
@@ -41,6 +41,6 @@ public QueueEvent getHandledQueueEvent() {
     }
 
     protected GravitonApi initGravitonApi() {
-        return null;
+        return gravitonApi;
     }
 }
diff --git a/src/test/java/com/github/libgraviton/workerbase/lib/TestWorkerException.java b/src/test/java/com/github/libgraviton/workerbase/lib/TestWorkerException.java
index 00e9a87d..9c9443d9 100644
--- a/src/test/java/com/github/libgraviton/workerbase/lib/TestWorkerException.java
+++ b/src/test/java/com/github/libgraviton/workerbase/lib/TestWorkerException.java
@@ -42,6 +42,6 @@ public Boolean shouldAutoRegister()
     }
 
     protected GravitonApi initGravitonApi() {
-        return null;
+        return gravitonApi;
     }
 }
diff --git a/src/test/java/com/github/libgraviton/workerbase/lib/TestWorkerNoAuto.java b/src/test/java/com/github/libgraviton/workerbase/lib/TestWorkerNoAuto.java
index 5c52a527..125bbece 100644
--- a/src/test/java/com/github/libgraviton/workerbase/lib/TestWorkerNoAuto.java
+++ b/src/test/java/com/github/libgraviton/workerbase/lib/TestWorkerNoAuto.java
@@ -42,7 +42,7 @@ public Boolean shouldAutoRegister()
     }
 
     protected GravitonApi initGravitonApi() {
-        return null;
+        return gravitonApi;
     }
     
 }