diff --git a/com.avaloq.tools.ddk.check.ui.test/META-INF/MANIFEST.MF b/com.avaloq.tools.ddk.check.ui.test/META-INF/MANIFEST.MF
index c475c69de..bf21036e7 100644
--- a/com.avaloq.tools.ddk.check.ui.test/META-INF/MANIFEST.MF
+++ b/com.avaloq.tools.ddk.check.ui.test/META-INF/MANIFEST.MF
@@ -29,8 +29,7 @@ Require-Bundle: com.avaloq.tools.ddk.check.ui,
 Export-Package: com.avaloq.tools.ddk.check.ui.test,
  com.avaloq.tools.ddk.check.ui.test.util,
  com.avaloq.tools.ddk.check
-Import-Package: org.slf4j,
- org.hamcrest.core,
+Import-Package: org.hamcrest.core,
  org.junit.runner;version="4.5.0",
  org.junit.runner.manipulation;version="4.5.0",
  org.junit.runner.notification;version="4.5.0",
diff --git a/com.avaloq.tools.ddk.xtext.test.core/META-INF/MANIFEST.MF b/com.avaloq.tools.ddk.xtext.test.core/META-INF/MANIFEST.MF
index 47dd4106a..820ccc4b2 100644
--- a/com.avaloq.tools.ddk.xtext.test.core/META-INF/MANIFEST.MF
+++ b/com.avaloq.tools.ddk.xtext.test.core/META-INF/MANIFEST.MF
@@ -26,7 +26,7 @@ Require-Bundle: com.avaloq.tools.ddk.xtext,
  org.eclipse.emf.common,
  com.avaloq.tools.ddk,
  junit-jupiter-api
-Import-Package: org.slf4j, org.apache.logging.log4j
+Import-Package: org.apache.logging.log4j
 Export-Package: com.avaloq.tools.ddk.xtext.test,
  com.avaloq.tools.ddk.xtext.test.contentassist,
  com.avaloq.tools.ddk.xtext.test.conversion,
diff --git a/com.avaloq.tools.ddk.xtext.test/META-INF/MANIFEST.MF b/com.avaloq.tools.ddk.xtext.test/META-INF/MANIFEST.MF
index cd82ca778..7da0eca88 100644
--- a/com.avaloq.tools.ddk.xtext.test/META-INF/MANIFEST.MF
+++ b/com.avaloq.tools.ddk.xtext.test/META-INF/MANIFEST.MF
@@ -46,8 +46,7 @@ Import-Package: com.avaloq.tools.ddk.check.runtime.test.core,
  com.avaloq.tools.ddk.xtext.test.export,
  com.avaloq.tools.ddk.xtext.test.format,
  com.avaloq.tools.ddk.xtext.ui.test,
- org.apache.logging.log4j,
- org.slf4j
+ org.apache.logging.log4j
 Export-Package: com.avaloq.tools.ddk.xtext,
  com.avaloq.tools.ddk.xtext.formatter,
  com.avaloq.tools.ddk.xtext.formatter.services,
diff --git a/ddk-target/ddk.target b/ddk-target/ddk.target
index 75884c0d2..746fd8a8f 100644
--- a/ddk-target/ddk.target
+++ b/ddk-target/ddk.target
@@ -57,7 +57,8 @@
     <unit id="org.apache.commons.lang3" version="3.20.0"/>
     <unit id="org.apache.logging.log4j.core" version="2.25.3"/>
     <unit id="org.apache.logging.log4j.api" version="2.25.3"/>
-    <unit id="org.apache.log4j" version="1.2.26"/> <!--use reload4j 1.2.26 for org.eclipse.xtext dependencies to log4j--> 
+    <unit id="org.apache.log4j" version="1.2.26"/> <!--use reload4j 1.2.26 for org.eclipse.xtext dependencies to log4j-->
+    <unit id="slf4j.nop" version="2.0.17"/>
   </location>
   <location includeAllPlatforms="false" includeConfigurePhase="false" includeMode="planner" includeSource="true" type="InstallableUnit">
     <repository location="https://download.eclipse.org/tools/orbit/simrel/maven-osgi/release/4.39.0"/>