diff --git a/src/org/camunda/latera/bss/connectors/hid/Hydra.groovy b/src/org/camunda/latera/bss/connectors/hid/Hydra.groovy
index 43d899bd..2fc147d2 100644
--- a/src/org/camunda/latera/bss/connectors/hid/Hydra.groovy
+++ b/src/org/camunda/latera/bss/connectors/hid/Hydra.groovy
@@ -75,7 +75,7 @@ class Hydra implements Ref, Message, DataType, AddParam, Good, Document, Contrac
       def group = (name =~ /^(.*)Id$/)
       if (group.size() > 0) {
         String noIdName = group[0][1]
-        if (params.containsKey(noIdName)) {
+        if (params.containsKey(noIdName) && params[noIdName] != null) {
           result[name] = getRefIdByCode(params[noIdName])
           keysToExclude.add(name)
           keysToExclude.add(noIdName)
diff --git a/src/org/camunda/latera/bss/connectors/hoper/Hydra.groovy b/src/org/camunda/latera/bss/connectors/hoper/Hydra.groovy
index 8e3d4afb..20053d24 100644
--- a/src/org/camunda/latera/bss/connectors/hoper/Hydra.groovy
+++ b/src/org/camunda/latera/bss/connectors/hoper/Hydra.groovy
@@ -47,7 +47,7 @@ class Hydra implements Main, Entity, Subject, Person, Company, File, Object, Add
       def group = (name =~ /^(.*)Id$/)
       if (group.size() > 0) {
         String noIdName = group[0][1]
-        if (params.containsKey(noIdName)) {
+        if (params.containsKey(noIdName) && params[noIdName] != null) {
           result[name] = getRefIdByCode(params[noIdName])
           keysToExclude.add(name)
           keysToExclude.add(noIdName)