diff --git a/python/sumk_dft.py b/python/sumk_dft.py
index a2a2557f..54721ca4 100644
--- a/python/sumk_dft.py
+++ b/python/sumk_dft.py
@@ -162,7 +162,7 @@ class SumkDFT:
         subgroup_present = 0
 
         if mpi.is_master_node():
-            ar = HDFArchive(self.hdf_file,'r')
+            ar = HDFArchive(self.hdf_file,'a')
             if subgrp in ar:
                 subgroup_present = True
                 # first read the necessary things:
@@ -227,7 +227,7 @@ class SumkDFT:
         """
 
         if not (mpi.is_master_node()): return # do nothing on nodes
-        ar = HDFArchive(self.hdf_file,'r')
+        ar = HDFArchive(self.hdf_file,'a')
         if not subgrp in ar: mpi.report("Loading %s failed!"%subgrp)
         list_to_return = []
         for it in things_to_load: 
diff --git a/python/sumk_dft_tools.py b/python/sumk_dft_tools.py
index 909b4f8f..93f014e5 100644
--- a/python/sumk_dft_tools.py
+++ b/python/sumk_dft_tools.py
@@ -598,7 +598,7 @@ class SumkDFTTools(SumkDFT):
        
         # Check if wien converter was called and read transport subgroup form hdf file
         if mpi.is_master_node():
-            ar = HDFArchive(self.hdf_file, 'r')
+            ar = HDFArchive(self.hdf_file, 'a')
             if not (self.transp_data in ar): raise IOError, "transport_distribution: No %s subgroup in hdf file found! Call convert_transp_input first." %self.transp_data
         self.read_transport_input_from_hdf()
         
diff --git a/python/symmetry.py b/python/symmetry.py
index 2ddec363..ad9d3720 100644
--- a/python/symmetry.py
+++ b/python/symmetry.py
@@ -53,7 +53,7 @@ class Symmetry:
 
         if mpi.is_master_node():
             #Read the stuff on master:
-            ar = HDFArchive(hdf_file,'r')
+            ar = HDFArchive(hdf_file,'a')
             if subgroup is None:
                 ar2 = ar
             else: