diff --git a/suites/aoip_encryption/register_a5_0_authopt.py b/suites/aoip_encryption/register_a5_0_authopt.py
index ff93cb8..0224ee0 100755
--- a/suites/aoip_encryption/register_a5_0_authopt.py
+++ b/suites/aoip_encryption/register_a5_0_authopt.py
@@ -11,8 +11,8 @@
 
 print('start network...')
 msc.set_authentication(False)
-msc.set_encryption('a5 0')
-bsc.set_encryption('a5 0')
+msc.set_encryption('a5_0')
+bsc.set_encryption('a5_0')
 hlr.start()
 stp.start()
 msc.start()
diff --git a/suites/aoip_encryption/register_a5_0_authreq.py b/suites/aoip_encryption/register_a5_0_authreq.py
index 051f5e2..114c628 100755
--- a/suites/aoip_encryption/register_a5_0_authreq.py
+++ b/suites/aoip_encryption/register_a5_0_authreq.py
@@ -11,8 +11,8 @@
 
 print('start network...')
 msc.set_authentication(True)
-msc.set_encryption('a5 0')
-bsc.set_encryption('a5 0')
+msc.set_encryption('a5_0')
+bsc.set_encryption('a5_0')
 hlr.start()
 stp.start()
 msc.start()
diff --git a/suites/aoip_encryption/register_a5_1_authreq.py b/suites/aoip_encryption/register_a5_1_authreq.py
index 11ee006..a84fa3a 100755
--- a/suites/aoip_encryption/register_a5_1_authreq.py
+++ b/suites/aoip_encryption/register_a5_1_authreq.py
@@ -11,8 +11,8 @@
 
 print('start network...')
 msc.set_authentication(True)
-msc.set_encryption('a5 1')
-bsc.set_encryption('a5 1')
+msc.set_encryption('a5_1')
+bsc.set_encryption('a5_1')
 hlr.start()
 stp.start()
 msc.start()