diff --git a/PRIVATE b/PRIVATE
index c9eed7180..d8ab8056d 160000
--- a/PRIVATE
+++ b/PRIVATE
@@ -1 +1 @@
-Subproject commit c9eed718041d098d7695871c1b123eae950b141d
+Subproject commit d8ab8056d6245ce42bec8953de9af1d7754867cf
diff --git a/lib/damask/config/material.py b/lib/damask/config/material.py
index a56c5d976..b070e986f 100644
--- a/lib/damask/config/material.py
+++ b/lib/damask/config/material.py
@@ -267,3 +267,14 @@ class Material():
     if newlen is not oldlen:
       print('Length of value was changed from %i to %i!'%(oldlen,newlen))
     
+  def add_value(self, part=None, 
+                         section=None, 
+                         key=None, 
+                         value=None):
+    if not isinstance(value,list): 
+      if not isinstance(value,str):
+        value = '%s'%value
+      value = [value]
+    print('adding %s:%s:%s with value %s '%(part.lower(),section.lower(),key.lower(),value))
+    self.data[part.lower()][section.lower()][key.lower()] = value
+    self.data[part.lower()][section.lower()]['__order__'] += [key.lower()]