diff --git a/README.md b/README.md
index 97a42ad..870c7ed 100644
--- a/README.md
+++ b/README.md
@@ -343,32 +343,30 @@ First of all there are some mandatory properties e.g. the information about your
 The GitOps-build-lib uses some docker images internally (To run Helm or Kubectl commands and specific Validators inside a docker container).  
 All of these have set default images, but you can change them if you wish to.
 
+```groovy
+def gitopsConfig = [
+    buildImages: [
+        // These are used to run helm and kubectl commands in the core logic
+        helm: 'ghcr.io/cloudogu/helm:3.5.4-1',
+        kubectl: 'lachlanevenson/k8s-kubectl:v1.19.3',
+        // These are used for each specific validator via an imageRef property inside the validators config. See [Validators] for examples.
+        kubeval: 'ghcr.io/cloudogu/helm:3.5.4-1',
+        helmKubeval: 'ghcr.io/cloudogu/helm:3.5.4-1',
+        yamllint: 'cytopia/yamllint:1.25-0.7'
+    ]
+]
+```
+
+Optional - if image is in a private repository, you can pass a `credentialsId` for pulling images.
+
 ```groovy
 def gitopsConfig = [
         buildImages: [
-            // These are used to run helm and kubectl commands in the core logic
-            // 
             helm: [ 
-                image: 'ghcr.io/cloudogu/helm:3.11.1-2'
-                credentialsId: 'myCredentials' (optional - only needed if image is in a private repository. CredentialsId is getting pulled from Jenkins credentials)
-                ],
-            kubectl: [ 
-                image: 'lachlanevenson/k8s-kubectl:v1.24.8'
-                credentialsId: 'myCredentials' (optional - only needed if image is in a private repository. CredentialsId is getting pulled from Jenkins credentials)
-                ],
-            // These are used for each specific validator via an imageRef property inside the validators config. See [Validators] for examples.
-            kubeval: [ 
-                image: 'ghcr.io/cloudogu/helm:3.5.4-1'
-                credentialsId: 'myCredentials' (optional - only needed if image is in a private repository. CredentialsId is getting pulled from Jenkins credentials)
+                image: 'ghcr.io/cloudogu/helm:3.11.1-2',
+                credentialsId: 'myCredentials'
                 ],
-            helmKubeval: [ 
-                image: 'ghcr.io/cloudogu/helm:3.5.4-1'
-                credentialsId: 'myCredentials' (optional - only needed if image is in a private repository. CredentialsId is getting pulled from Jenkins credentials)
-                ],
-            yamllint: [
-                image: 'cytopia/yamllint:1.25-0.9'
-                credentialsId: 'myCredentials' (optional - only needed if image is in a private repository. CredentialsId is getting pulled from Jenkins credentials)
-                ]
+            // ...
         ]
 ]
 ```
diff --git a/src/com/cloudogu/gitopsbuildlib/docker/DockerWrapper.groovy b/src/com/cloudogu/gitopsbuildlib/docker/DockerWrapper.groovy
index 089e22a..8b3694f 100644
--- a/src/com/cloudogu/gitopsbuildlib/docker/DockerWrapper.groovy
+++ b/src/com/cloudogu/gitopsbuildlib/docker/DockerWrapper.groovy
@@ -10,13 +10,15 @@ class DockerWrapper {
     void withDockerImage(def imageConfig, Closure body) {
         // imageConfig can either be a Map or a String, depending on the old or the new format if this field
         // The old format was a String containing an image url. The new one is a map with an image url and optional credentials
-        if(imageConfig instanceof Map && imageConfig.containsKey('credentialsId') && imageConfig.credentialsId) {
-            def registryUrl = getRegistryUrlFromImage(imageConfig.image)
-            script.docker.withRegistry("https://${registryUrl}", imageConfig.credentialsId) {
+        if (imageConfig instanceof Map) {
+            if (imageConfig.containsKey('credentialsId') && imageConfig.credentialsId) {
+                def registryUrl = getRegistryUrlFromImage(imageConfig.image)
+                script.docker.withRegistry("https://${registryUrl}", imageConfig.credentialsId) {
+                    runDockerImage(imageConfig.image, body)
+                }
+            } else {
                 runDockerImage(imageConfig.image, body)
             }
-        } else if (imageConfig instanceof Map && imageConfig.containsKey('image')){
-            runDockerImage(imageConfig.image, body)
         } else {
             // When imageConfig is a String
             runDockerImage(imageConfig, body)
diff --git a/test/com/cloudogu/gitopsbuildlib/docker/DockerWrapperTest.groovy b/test/com/cloudogu/gitopsbuildlib/docker/DockerWrapperTest.groovy
new file mode 100644
index 0000000..fd55cfa
--- /dev/null
+++ b/test/com/cloudogu/gitopsbuildlib/docker/DockerWrapperTest.groovy
@@ -0,0 +1,48 @@
+package com.cloudogu.gitopsbuildlib.docker
+
+import com.cloudogu.gitopsbuildlib.ScriptMock
+import org.junit.jupiter.api.Test
+
+import static org.assertj.core.api.Assertions.assertThat 
+
+class DockerWrapperTest {
+
+    public static final String EXPECTED_IMAGE = 'ghcr.io/cloudogu/helm:3.11.1-2'
+    
+    def scriptMock = new ScriptMock()
+    
+    def dockerWrapper = new DockerWrapper(scriptMock.mock)
+    
+    def imageConfigMap = [
+        image: EXPECTED_IMAGE,
+    ]
+    def imageConfigMapWithCredentials = [
+        image: EXPECTED_IMAGE,
+        credentialsId: 'myCredentials'
+    ]
+    def imageConfigString = EXPECTED_IMAGE
+    
+    @Test
+    void 'works with imageConfig string'() {
+
+        dockerWrapper.withDockerImage(imageConfigString) {
+        }
+        assertThat(scriptMock.dockerMock.actualImages[0]).isEqualTo(EXPECTED_IMAGE)
+    }
+    
+    @Test
+    void 'works with imageConfig Map'() {
+        dockerWrapper.withDockerImage(imageConfigMap) {
+        }
+        assertThat(scriptMock.dockerMock.actualImages[0]).isEqualTo(EXPECTED_IMAGE)
+    }
+    
+    @Test
+    void 'works with imageConfig Map with Credentials'() {
+        dockerWrapper.withDockerImage(imageConfigMapWithCredentials) {
+        }
+        assertThat(scriptMock.dockerMock.actualImages[0]).isEqualTo(EXPECTED_IMAGE)
+        assertThat(scriptMock.dockerMock.actualRegistryArgs[0]).isEqualTo('https://ghcr.io/cloudogu')
+        assertThat(scriptMock.dockerMock.actualRegistryArgs[1]).isEqualTo('myCredentials')
+    }
+}