diff --git a/gcodeutils/gcode_line.pyx b/gcodeutils/gcode_line.pyx
new file mode 100644
index 0000000..0c42526
--- /dev/null
+++ b/gcodeutils/gcode_line.pyx
@@ -0,0 +1,327 @@
+# This file is copied from GCoder.
+#
+# GCoder is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# GCoder is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Printrun.  If not, see <http://www.gnu.org/licenses/>.
+
+from libc.stdlib cimport malloc, free
+from libc.stdint cimport uint8_t, uint32_t
+from libc.string cimport strlen, strncpy
+
+cdef char*copy_string(object value):
+    cdef char*orig = value
+    str_len = len(orig)
+    cdef char*array = <char *> malloc(str_len + 1)
+    strncpy(array, orig, str_len)
+    array[str_len] = 0;
+    return array
+
+cdef enum BitPos:
+    pos_raw = 1 << 0
+    pos_command = 1 << 1
+    pos_is_move = 1 << 2
+    pos_x = 1 << 3
+    pos_y = 1 << 4
+    pos_z = 1 << 5
+    pos_e = 1 << 6
+    pos_f = 1 << 7
+    pos_i = 1 << 8
+    pos_j = 1 << 9
+    pos_relative = 1 << 10
+    pos_relative_e = 1 << 11
+    pos_extruding = 1 << 12
+    pos_current_x = 1 << 13
+    pos_current_y = 1 << 14
+    pos_current_z = 1 << 15
+    pos_current_tool = 1 << 16
+    pos_gcview_end_vertex = 1 << 17
+    pos_current_e = 1 << 18
+    pos_current_f = 1 << 19
+# WARNING: don't use bits 24 to 31 as we store current_tool there
+
+cdef inline uint32_t has_var(uint32_t status, uint32_t pos):
+    return status & pos
+
+cdef inline uint32_t set_has_var(uint32_t status, uint32_t pos):
+    return status | pos
+
+cdef inline uint32_t unset_has_var(uint32_t status, uint32_t pos):
+    return status & ~pos
+
+cdef class GLine:
+    cdef char*_raw
+    cdef char*_command
+    cdef float _x, _y, _z, _e, _f, _i, _j
+    cdef float _current_x, _current_y, _current_z, _current_e, _current_f
+    cdef uint32_t _gcview_end_vertex
+    cdef uint32_t _status
+
+    __slots__ = ()
+
+    def __cinit__(self):
+        self._status = 0
+        self._raw = NULL
+        self._command = NULL
+
+    def __init__(self, line):
+        self.raw = line
+
+    def __dealloc__(self):
+        if self._raw != NULL: free(self._raw)
+        if self._command != NULL: free(self._command)
+
+    property x:
+        def __get__(self):
+            if has_var(self._status, pos_x):
+                return self._x
+            else:
+                return None
+        def __set__(self, value):
+            self._x = value
+            self._status = set_has_var(self._status, pos_x)
+    property y:
+        def __get__(self):
+            if has_var(self._status, pos_y):
+                return self._y
+            else:
+                return None
+        def __set__(self, value):
+            self._y = value
+            self._status = set_has_var(self._status, pos_y)
+    property z:
+        def __get__(self):
+            if has_var(self._status, pos_z):
+                return self._z
+            else:
+                return None
+        def __set__(self, value):
+            self._z = value
+            self._status = set_has_var(self._status, pos_z)
+    property e:
+        def __get__(self):
+            if has_var(self._status, pos_e):
+                return self._e
+            else:
+                return None
+        def __set__(self, value):
+            self._e = value
+            self._status = set_has_var(self._status, pos_e)
+    property current_e:
+        def __get__(self):
+            if has_var(self._status, pos_e):
+                return self._current_e
+            else:
+                return None
+        def __set__(self, value):
+            self._current_e = value
+            self._status = set_has_var(self._status, pos_current_e)
+    property f:
+        def __get__(self):
+            if has_var(self._status, pos_f):
+                return self._f
+            else:
+                return None
+        def __set__(self, value):
+            self._f = value
+            self._status = set_has_var(self._status, pos_f)
+
+    property current_f:
+        def __get__(self):
+            if has_var(self._status, pos_f):
+                return self._current_f
+            else:
+                return None
+        def __set__(self, value):
+            self._current_f = value
+            self._status = set_has_var(self._status, pos_current_f)
+    property i:
+        def __get__(self):
+            if has_var(self._status, pos_i):
+                return self._i
+            else:
+                return None
+        def __set__(self, value):
+            self._i = value
+            self._status = set_has_var(self._status, pos_i)
+    property j:
+        def __get__(self):
+            if has_var(self._status, pos_j):
+                return self._j
+            else:
+                return None
+        def __set__(self, value):
+            self._j = value
+            self._status = set_has_var(self._status, pos_j)
+    property is_move:
+        def __get__(self):
+            if has_var(self._status, pos_is_move):
+                return True
+            else:
+                return False
+        def __set__(self, value):
+            if value:
+                self._status = set_has_var(self._status, pos_is_move)
+            else:
+                self._status = unset_has_var(self._status, pos_is_move)
+    property relative:
+        def __get__(self):
+            if has_var(self._status, pos_relative):
+                return True
+            else:
+                return False
+        def __set__(self, value):
+            if value:
+                self._status = set_has_var(self._status, pos_relative)
+            else:
+                self._status = unset_has_var(self._status, pos_relative)
+    property relative_e:
+        def __get__(self):
+            if has_var(self._status, pos_relative_e):
+                return True
+            else:
+                return False
+        def __set__(self, value):
+            if value:
+                self._status = set_has_var(self._status, pos_relative_e)
+            else:
+                self._status = unset_has_var(self._status, pos_relative_e)
+    property extruding:
+        def __get__(self):
+            if has_var(self._status, pos_extruding):
+                return True
+            else:
+                return False
+        def __set__(self, value):
+            if value:
+                self._status = set_has_var(self._status, pos_extruding)
+            else:
+                self._status = unset_has_var(self._status, pos_extruding)
+    property current_x:
+        def __get__(self):
+            if has_var(self._status, pos_current_x):
+                return self._current_x
+            else:
+                return None
+        def __set__(self, value):
+            self._current_x = value
+            self._status = set_has_var(self._status, pos_current_x)
+    property current_y:
+        def __get__(self):
+            if has_var(self._status, pos_current_y):
+                return self._current_y
+            else:
+                return None
+        def __set__(self, value):
+            self._current_y = value
+            self._status = set_has_var(self._status, pos_current_y)
+    property current_z:
+        def __get__(self):
+            if has_var(self._status, pos_current_z):
+                return self._current_z
+            else:
+                return None
+        def __set__(self, value):
+            self._current_z = value
+            self._status = set_has_var(self._status, pos_current_z)
+    property current_tool:
+        def __get__(self):
+            if has_var(self._status, pos_current_tool):
+                return self._status >> 24
+            else:
+                return None
+        def __set__(self, value):
+            self._status = (self._status & ((1 << 24) - 1)) | (value << 24)
+            self._status = set_has_var(self._status, pos_current_tool)
+    property gcview_end_vertex:
+        def __get__(self):
+            if has_var(self._status, pos_gcview_end_vertex):
+                return self._gcview_end_vertex
+            else:
+                return None
+        def __set__(self, value):
+            self._gcview_end_vertex = value
+            self._status = set_has_var(self._status, pos_gcview_end_vertex)
+    property raw:
+        def __get__(self):
+            if has_var(self._status, pos_raw):
+                return self._raw
+            else:
+                return None
+        def __set__(self, value):
+            # WARNING: memory leak could happen here, as we don't do the following :
+            # if self._raw != NULL: free(self._raw)
+            self._raw = copy_string(value)
+            self._status = set_has_var(self._status, pos_raw)
+    property command:
+        def __get__(self):
+            if has_var(self._status, pos_command):
+                return self._command
+            else:
+                return None
+        def __set__(self, value):
+            # WARNING: memory leak could happen here, as we don't do the following :
+            # if self._command != NULL: free(self._command)
+            self._command = copy_string(value)
+            self._status = set_has_var(self._status, pos_command)
+
+cdef class GLightLine:
+    cdef char*_raw
+    cdef char*_command
+    cdef uint8_t _status
+
+    __slots__ = ()
+
+    def __cinit__(self):
+        self._status = 0
+        self._raw = NULL
+        self._command = NULL
+
+    def __init__(self, line):
+        self.raw = line
+
+    def __dealloc__(self):
+        if self._raw != NULL: free(self._raw)
+        if self._command != NULL: free(self._command)
+
+    property raw:
+        def __get__(self):
+            if has_var(self._status, pos_raw):
+                return self._raw
+            else:
+                return None
+        def __set__(self, value):
+            # WARNING: memory leak could happen here, as we don't do the following :
+            # if self._raw != NULL: free(self._raw)
+            self._raw = copy_string(value)
+            self._status = set_has_var(self._status, pos_raw)
+    property command:
+        def __get__(self):
+            if has_var(self._status, pos_command):
+                return self._command
+            else:
+                return None
+        def __set__(self, value):
+            # WARNING: memory leak could happen here, as we don't do the following :
+            # if self._command != NULL: free(self._command)
+            self._command = copy_string(value)
+            self._status = set_has_var(self._status, pos_command)
+    property is_move:
+        def __get__(self):
+            if has_var(self._status, pos_is_move):
+                return True
+            else:
+                return False
+        def __set__(self, value):
+            if value:
+                self._status = set_has_var(self._status, pos_is_move)
+            else:
+                self._status = unset_has_var(self._status, pos_is_move)
diff --git a/gcodeutils/gcoder.py b/gcodeutils/gcoder.py
index 44bcffc..4571da2 100755
--- a/gcodeutils/gcoder.py
+++ b/gcodeutils/gcoder.py
@@ -105,19 +105,14 @@ def __getattr__(self, name):
 
 
 # TODO: reenable loading of C optimised representation of GCode
-# try:
-# import gcoder_line
-#
-# Line = gcoder_line.GLine
-# LightLine = gcoder_line.GLightLine
-# except Exception as e:
-#     logging.warning("Memory-efficient GCoder implementation unavailable: %s" % e)
-#     Line = PyLine
-#     LightLine = PyLightLine
-
-Line = PyLine
-LightLine = PyLightLine
-
+try:
+    from gcodeutils import gcode_line
+    Line = gcode_line.GLine
+    LightLine = gcode_line.GLightLine
+except ImportError:
+    logging.warning("Memory-efficient GCoder implementation unavailable")
+    Line = PyLine
+    LightLine = PyLightLine
 
 def find_specific_code(line, code):
     exp = specific_exp % code
diff --git a/setup.py b/setup.py
index 6ad014e..33319fb 100644
--- a/setup.py
+++ b/setup.py
@@ -10,6 +10,7 @@
 # To use a consistent encoding
 from codecs import open
 from os import path
+from Cython.Build import cythonize
 
 here = path.abspath(path.dirname(__file__))
 
@@ -89,6 +90,8 @@
         'test': ['nose'],
     },
 
+    ext_modules = cythonize("gcodeutils/gcode_line.pyx"),
+
     # If there are data files included in your packages that need to be
     # installed, specify them here.  If using Python 2.6 or less, then these
     # have to be included in MANIFEST.in as well.