diff --git a/python/obitools3/apps/config.pxd b/python/obitools3/apps/config.pxd
index d055eef..74c595f 100644
--- a/python/obitools3/apps/config.pxd
+++ b/python/obitools3/apps/config.pxd
@@ -6,5 +6,5 @@ cpdef str getRootConfigName()
 cdef dict buildDefaultConfiguration(str root_config_name,
                                     dict  config)
 
-cpdef dict getConfiguration(str root_config_name,
-                                    dict  config)
\ No newline at end of file
+cpdef dict getConfiguration(str root_config_name=?,
+                                    dict  config=?)
\ No newline at end of file
diff --git a/python/obitools3/apps/config.pyx b/python/obitools3/apps/config.pyx
index 55178ec..c8e3baa 100644
--- a/python/obitools3/apps/config.pyx
+++ b/python/obitools3/apps/config.pyx
@@ -12,7 +12,7 @@ from .command   import  getCommandsList
 from .logging   cimport getLogger
 from .arguments cimport buildArgumentParser
 
-from obitools3.version import version
+from ..version import version
 from _curses import version
 
 cdef dict __default_config__ = {}
@@ -57,13 +57,20 @@ cdef dict buildDefaultConfiguration(str root_config_name,
     return __default_config__
         
 
-cpdef dict getConfiguration(str root_config_name,
-                            dict  config):
+cpdef dict getConfiguration(str root_config_name="__default__",
+                            dict  config={}):
     global __default_config__
 
     if '__done__' in __default_config__:
         return __default_config__
     
+    if root_config_name=="__default__":
+        raise RuntimeError("No root_config_name specified")
+    
+    if not config:
+        raise RuntimeError("Base configuration is empty")
+    
+    
     
     config =  buildDefaultConfiguration(root_config_name,
                                         config)