diff --git a/openbis/source/java/ch/systemsx/cisd/openbis/plugin/generic/server/SampleRegisterOrUpdateUtil.java b/openbis/source/java/ch/systemsx/cisd/openbis/plugin/generic/server/SampleRegisterOrUpdateUtil.java
index f1f56d39afb7be4881d9b3c6c095043b0b38ebbc..182cb9137e383dacfb8a6de653b6eb3150182fde 100644
--- a/openbis/source/java/ch/systemsx/cisd/openbis/plugin/generic/server/SampleRegisterOrUpdateUtil.java
+++ b/openbis/source/java/ch/systemsx/cisd/openbis/plugin/generic/server/SampleRegisterOrUpdateUtil.java
@@ -122,6 +122,7 @@ public class SampleRegisterOrUpdateUtil
             return false;
         }
 
+        @SuppressWarnings("null")
         String newSampleSubCode = newSampleIdentifier.getSampleSubCode();
         if (existingSample.getSubCode().equalsIgnoreCase(newSampleSubCode) == false)
         {