diff --git a/common/python/nomadcore/local_backend.py b/common/python/nomadcore/local_backend.py
index d813849cff30b0f5c9156fbb0c475ee51443d639..49cc66fff771cd8f92fcd462fa98575b0006a410 100644
--- a/common/python/nomadcore/local_backend.py
+++ b/common/python/nomadcore/local_backend.py
@@ -120,7 +120,7 @@ class LocalBackend(object):
         first value of MetaName in gindex in the backend"""
         dataManager = self.dataManagers[metaName]
 
-        if self.debug:
+        if self.debug and value is not None:
 
             # Check that the value is actually of scalar type
             value_type = type(value)