diff --git a/kbinxml/sixbit.py b/kbinxml/sixbit.py
index 4cbc1f7..17e3247 100644
--- a/kbinxml/sixbit.py
+++ b/kbinxml/sixbit.py
@@ -1,18 +1,20 @@
 # python 3 style, ints instead of b''
 from builtins import bytes
-from bitarray import bitarray
 
 charmap = '0123456789:ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz'
-bytemap = {charmap[i] : bytes(chr(i).encode()) for i in range(len(charmap))}
+bytemap = {charmap[i] : i for i in range(len(charmap))}
 
 def pack_sixbit(string, byteBuf):
     chars = [bytemap[x] for x in string]
-    bits = bitarray(endian='big')
+    padding = 8 - (len(string)*6 % 8)
+    if padding == 8:
+        padding = 0
+    bits = 0
     for c in chars:
-        bits.frombytes(c)
-        # leave only the 6 bits we care for
-        del bits[-8:-6]
-    data = bytes(bits.tobytes())
+        bits <<= 6
+        bits |= c
+    bits <<= padding
+    data = bytes(bits.to_bytes((len(string)*6 + padding) // 8, byteorder='big'))
     byteBuf.append_bytes((len(string),))
     byteBuf.append_bytes(data)
 
@@ -20,8 +22,13 @@ def unpack_sixbit(byteBuf):
     length = byteBuf.get_u8()
     length_bits = length * 6
     length_bytes = (length_bits + 7) // 8
-    bitBuf = bitarray(endian='big')
-    bitBuf.frombytes(bytes(byteBuf.get_bytes(length_bytes)))
-    result = [bytes(bitBuf[offset:offset+6].tobytes())[0] >> 2
-              for offset in range(0, length_bits, 6)]
-    return ''.join([charmap[x] for x in result])
+    padding = 8 - (length_bits % 8)
+    if padding == 8:
+        padding = 0
+    bits = int.from_bytes(bytes(byteBuf.get_bytes(length_bytes)), byteorder='big')
+    bits >>= padding
+    result = []
+    for _ in range(length):
+        result.append(bits & 0b111111)
+        bits >>= 6
+    return ''.join([charmap[x] for x in result[::-1]])
diff --git a/setup.py b/setup.py
index d43453e..89baa7d 100644
--- a/setup.py
+++ b/setup.py
@@ -3,13 +3,12 @@ import sys
 
 
 requires = [
-        'bitarray',
         'lxml',
 ]
 if sys.version_info < (3,0):
     requires.append('future')
 
-version = '1.4'
+version = '1.5'
 setup(
     name='kbinxml',
     description="Decoder/encoder for Konami's binary XML format",