diff --git a/python/trx/ctrl_if_bb.py b/python/trx/ctrl_if_bb.py
index 4814263..1c21c55 100644
--- a/python/trx/ctrl_if_bb.py
+++ b/python/trx/ctrl_if_bb.py
@@ -22,7 +22,7 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
-from ctrl_if import CTRLInterface
+from .ctrl_if import CTRLInterface
 
 class CTRLInterfaceBB(CTRLInterface):
 	def __init__(self, trx, *ctrl_if_args):