diff --git a/sernet.gs.service/src/serialization-filter-class-whitelist.txt b/sernet.gs.service/src/serialization-filter-class-whitelist.txt
index c6eb6533b..025493774 100644
--- a/sernet.gs.service/src/serialization-filter-class-whitelist.txt
+++ b/sernet.gs.service/src/serialization-filter-class-whitelist.txt
@@ -9,6 +9,7 @@ java.lang.Enum
 java.lang.Exception
 java.lang.Long
 java.lang.NoClassDefFoundError
+java.lang.NullPointerException
 java.lang.Number
 java.lang.invoke.SerializedLambda
 java.lang.reflect.InvocationTargetException