diff --git a/scm-core/src/main/java/sonia/scm/security/PermissionDescriptor.java b/scm-core/src/main/java/sonia/scm/security/PermissionDescriptor.java
index 8d95131ee6..3ea7737b4e 100644
--- a/scm-core/src/main/java/sonia/scm/security/PermissionDescriptor.java
+++ b/scm-core/src/main/java/sonia/scm/security/PermissionDescriptor.java
@@ -100,7 +100,7 @@ public class PermissionDescriptor implements Serializable
   @Override
   public int hashCode()
   {
-    return value.hashCode();
+    return value == null? -1: value.hashCode();
   }
 
   /**