diff --git a/Makefile b/Makefile
index 70cc54d..c5b57ba 100644
--- a/Makefile
+++ b/Makefile
@@ -8,7 +8,7 @@ ext:
 	python setup.py build_ext --inplace
 
 test:
-	python -m pytest
+	python -m pytest tests
 
 clean:
 	find pyModeS/decoder -type f -name '*.c' -delete
diff --git a/pyModeS/__init__.py b/pyModeS/__init__.py
index 4dacfcd..488cb89 100644
--- a/pyModeS/__init__.py
+++ b/pyModeS/__init__.py
@@ -2,11 +2,11 @@ import os
 import warnings
 
 try:
-    from .decoder import c_common as common
-    from .decoder.c_common import *
+    from . import c_common as common
+    from .c_common import *
 except:
-    from .decoder import common
-    from .decoder.common import *
+    from . import common
+    from .common import *
 
 from .decoder import tell
 from .decoder import adsb
@@ -15,6 +15,9 @@ from .decoder import bds
 from .extra import aero
 from .extra import tcpclient
 
+from .encoder import encode_adsb
+
+
 warnings.simplefilter("once", DeprecationWarning)
 
 dirpath = os.path.dirname(os.path.realpath(__file__))
diff --git a/pyModeS/decoder/c_common.pxd b/pyModeS/c_common.pxd
similarity index 100%
rename from pyModeS/decoder/c_common.pxd
rename to pyModeS/c_common.pxd
diff --git a/pyModeS/decoder/c_common.pyx b/pyModeS/c_common.pyx
similarity index 100%
rename from pyModeS/decoder/c_common.pyx
rename to pyModeS/c_common.pyx
diff --git a/pyModeS/decoder/common.py b/pyModeS/common.py
similarity index 98%
rename from pyModeS/decoder/common.py
rename to pyModeS/common.py
index 47ecb94..cb2df95 100644
--- a/pyModeS/decoder/common.py
+++ b/pyModeS/common.py
@@ -41,10 +41,8 @@ def crc(msg, encode=False):
     # the CRC generator
     G = [int("11111111", 2), int("11111010", 2), int("00000100", 2), int("10000000", 2)]
 
-    if encode and isinstance(msg, str):
+    if encode:
         msg = msg[:-6] + "000000"
-    elif encode:
-        msg = msg[:-6] + b"000000"
 
     msgbin = hex2bin(msg)
     msgbin_split = wrap(msgbin, 8)
diff --git a/pyModeS/decoder/bds/__init__.py b/pyModeS/decoder/bds/__init__.py
index 14b9959..d6e0163 100644
--- a/pyModeS/decoder/bds/__init__.py
+++ b/pyModeS/decoder/bds/__init__.py
@@ -21,12 +21,7 @@ Common functions for Mode-S decoding
 import numpy as np
 
 from pyModeS.extra import aero
-
-try:
-    from pyModeS.decoder import c_common as common
-except:
-    from pyModeS.decoder import common
-
+from pyModeS import common
 
 from pyModeS.decoder.bds import (
     bds05,
diff --git a/setup.py b/setup.py
index 20aba5d..3affbfc 100644
--- a/setup.py
+++ b/setup.py
@@ -19,7 +19,7 @@ from setuptools import setup, find_packages
 from setuptools.extension import Extension
 from Cython.Build import cythonize
 
-extensions = [Extension("pyModeS.decoder.c_common", ["pyModeS/decoder/c_common.pyx"])]
+extensions = [Extension("pyModeS.c_common", ["pyModeS/c_common.pyx"])]
 
 
 # To use a consistent encoding
diff --git a/tests/test_common.py b/tests/test_common.py
index 571b0cf..6149ca4 100644
--- a/tests/test_common.py
+++ b/tests/test_common.py
@@ -1,4 +1,4 @@
-from pyModeS.decoder import common
+from pyModeS import common
 
 
 def test_conversions():