diff --git a/python/obitools3/commands/import.pyx b/python/obitools3/commands/import.pyx
index 377ad0a..f2fe2a5 100755
--- a/python/obitools3/commands/import.pyx
+++ b/python/obitools3/commands/import.pyx
@@ -25,7 +25,8 @@ from obitools3.dms.capi.obiview cimport VIEW_TYPE_NUC_SEQS, \
                                         DEFINITION_COLUMN, \
                                         QUALITY_COLUMN, \
                                         COUNT_COLUMN, \
-                                        TAXID_COLUMN
+                                        TAXID_COLUMN, \
+                                        MERGED_PREFIX
                                         
 from obitools3.dms.capi.obidms cimport obi_import_view
 
@@ -163,7 +164,7 @@ def run(config):
         taxo.write(taxo_name)
         taxo.close()
         o_dms.record_command_line(" ".join(sys.argv[1:]))
-        o_dms.close()
+        o_dms.close(force=True)
         logger("info", "Done.")
         return
 
@@ -217,11 +218,14 @@ def run(config):
                 logger("info", "Read %d entries", i)
     
             for tag in entry :
+                newtag = tag
+                if tag[:7] == b"merged_":
+                    newtag = MERGED_PREFIX+tag[7:]
                 if type(entry[tag]) == dict :
                     if tag in dict_dict:
-                        dict_dict[tag][0].update(entry[tag].keys())
+                        dict_dict[newtag][0].update(entry[tag].keys())
                     else:
-                        dict_dict[tag] = [set(entry[tag].keys()), get_obitype(entry[tag])]
+                        dict_dict[newtag] = [set(entry[tag].keys()), get_obitype(entry[tag])]
             i+=1
         
         if pb is not None:
@@ -288,6 +292,8 @@ def run(config):
                     tag = TAXID_COLUMN
                 if tag == b"count":
                     tag = COUNT_COLUMN
+                if tag[:7] == b"merged_":
+                    tag = MERGED_PREFIX+tag[7:]
                     
                 if tag not in dcols :
                      
@@ -328,8 +334,8 @@ def run(config):
                     try:
                         # Check that it's not the case where the first entry contained a dict of length 1 and now there is a new key                        
                         if type(value) == dict and \
-                            dcols[tag][0].nb_elements_per_line == 1 and len(value.keys()) == 1 \
-                            and dcols[tag][0].elements_names[0] != list(value.keys())[0] :
+                            dcols[tag][0].nb_elements_per_line == 1 \
+                            and set(dcols[tag][0].elements_names) != set(value.keys()) :
                             raise IndexError  # trigger column rewrite
                         
                         # Fill value
@@ -402,7 +408,7 @@ def run(config):
     except AttributeError:
         pass
     try:
-        output[0].close()
+        output[0].close(force=True)
     except AttributeError:
         pass