diff --git a/python/demapping/gsm_bcch_ccch_demapper.py b/python/demapping/gsm_bcch_ccch_demapper.py
index e036831..06baa62 100644
--- a/python/demapping/gsm_bcch_ccch_demapper.py
+++ b/python/demapping/gsm_bcch_ccch_demapper.py
@@ -32,10 +32,10 @@
 import grgsm
 
 
-class gsm_bcch_ccch_demapper(grgsm.hier_block):
+class gsm_bcch_ccch_demapper(gr.hier_block2):
 
     def __init__(self, timeslot_nr=0):
-        grgsm.hier_block.__init__(
+        gr.hier_block2.__init__(
             self, "BCCH + CCCH demapper",
             gr.io_signature(0, 0, 0),
             gr.io_signature(0, 0, 0),
diff --git a/python/demapping/gsm_bcch_ccch_sdcch4_demapper.py b/python/demapping/gsm_bcch_ccch_sdcch4_demapper.py
index bff67a4..f025a70 100644
--- a/python/demapping/gsm_bcch_ccch_sdcch4_demapper.py
+++ b/python/demapping/gsm_bcch_ccch_sdcch4_demapper.py
@@ -32,10 +32,10 @@
 import grgsm
 
 
-class gsm_bcch_ccch_sdcch4_demapper(grgsm.hier_block):
+class gsm_bcch_ccch_sdcch4_demapper(gr.hier_block2):
 
     def __init__(self, timeslot_nr=0):
-        grgsm.hier_block.__init__(
+        gr.hier_block2.__init__(
             self, "BCCH + CCCH + SDCCH/4 demapper",
             gr.io_signature(0, 0, 0),
             gr.io_signature(0, 0, 0),
diff --git a/python/demapping/gsm_sdcch8_demapper.py b/python/demapping/gsm_sdcch8_demapper.py
index b412594..30450bf 100644
--- a/python/demapping/gsm_sdcch8_demapper.py
+++ b/python/demapping/gsm_sdcch8_demapper.py
@@ -32,10 +32,10 @@
 import grgsm
 
 
-class gsm_sdcch8_demapper(grgsm.hier_block):
+class gsm_sdcch8_demapper(gr.hier_block2):
 
     def __init__(self, timeslot_nr=1):
-        grgsm.hier_block.__init__(
+        gr.hier_block2.__init__(
             self, "SDCCH/8 demapper",
             gr.io_signature(0, 0, 0),
             gr.io_signature(0, 0, 0),