diff --git a/scm-core/src/main/java/sonia/scm/plugin/InstalledPlugin.java b/scm-core/src/main/java/sonia/scm/plugin/InstalledPlugin.java
index 602378fe6a..09f05e2c99 100644
--- a/scm-core/src/main/java/sonia/scm/plugin/InstalledPlugin.java
+++ b/scm-core/src/main/java/sonia/scm/plugin/InstalledPlugin.java
@@ -143,9 +143,6 @@ public final class InstalledPlugin implements Plugin
     this.uninstallable = uninstallable;
   }
 
-  public void markAsCore() {
-    this.core = true;
-  }
 //~--- fields ---------------------------------------------------------------
 
   /** plugin class loader */
@@ -160,7 +157,7 @@ public final class InstalledPlugin implements Plugin
   /** plugin web resource loader */
   private final WebResourceLoader webResourceLoader;
 
-  private boolean core;
+  private final boolean core;
 
   private boolean markedForUninstall = false;
   private boolean uninstallable = false;
diff --git a/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java b/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java
index a73c2795ed..d54645f10d 100644
--- a/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java
+++ b/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java
@@ -215,11 +215,6 @@ public class DefaultPluginManager implements PluginManager {
       && dependencyTracker.mayUninstall(p.getDescriptor().getInformation().getName());
   }
 
-  private void markAsCore(InstalledPlugin plugin) {
-    createMarkerFile(plugin, PluginConstants.FILE_CORE);
-    plugin.markAsCore();
-  }
-
   private void createMarkerFile(InstalledPlugin plugin, String markerFile) {
     try {
       Files.createFile(plugin.getDirectory().resolve(markerFile));