diff --git a/pySim/sysmocom_sja2.py b/pySim/sysmocom_sja2.py
index dd876aaa..97de5a56 100644
--- a/pySim/sysmocom_sja2.py
+++ b/pySim/sysmocom_sja2.py
@@ -19,7 +19,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from struct import unpack
 from construct import FlagsEnum, Byte, Struct, Int8ub, Bytes, Mapping, Enum, Padding, BitsInteger
-from construct import Bit, this, Int32ub, Int16ub, Nibble, BytesInteger, GreedyRange
+from construct import Bit, this, Int32ub, Int16ub, Nibble, BytesInteger, GreedyRange, Const
 from construct import Optional as COptional
 
 from pySim.utils import *