diff --git a/doc/topics/install.rst b/doc/topics/install.rst
index be508ae30f..4cfb44d0b2 100644
--- a/doc/topics/install.rst
+++ b/doc/topics/install.rst
@@ -20,6 +20,7 @@ Prerequisites
     * Optional: unoconv http://dag.wieers.com/home-made/unoconv/)
     * Optional: sphinx (http://sphinx.pocoo.org/)
     * Optional: simplejson (http://undefined.org/python/#simplejson)
+    * Optional: cdecimal (http://www.bytereef.org/mpdecimal/index.html)
 
 Install Tryton
 ==============
diff --git a/setup.py b/setup.py
index 6046e70bfe..34e7a4214d 100644
--- a/setup.py
+++ b/setup.py
@@ -71,6 +71,7 @@ setup(name=PACKAGE,
         'graphviz': ['pydot'],
         'timezone': ['pytz'],
         'simplejson': ['simplejson'],
+        'cdecimal': ['cdecimal'],
     },
     zip_safe=False,
     test_suite='trytond.tests',
diff --git a/trytond/config.py b/trytond/config.py
index 0cdb678dbf..098462d650 100644
--- a/trytond/config.py
+++ b/trytond/config.py
@@ -1,6 +1,16 @@
 #This file is part of Tryton.  The COPYRIGHT file at the top level of
 #this repository contains the full copyright notices and license terms.
-import ConfigParser, os, sys
+import sys
+try:
+    import cdecimal
+    # Use cdecimal globally
+    if 'decimal' not in sys.modules:
+        sys.modules['decimal'] = cdecimal
+except ImportError:
+    import decimal
+    sys.modules['cdecimal'] = decimal
+import os
+import ConfigParser
 
 def get_hostname(netloc):
     if '[' in netloc and ']' in netloc:
diff --git a/trytond/tests/test_exportdata.py b/trytond/tests/test_exportdata.py
index 568f537dba..64984f76c4 100644
--- a/trytond/tests/test_exportdata.py
+++ b/trytond/tests/test_exportdata.py
@@ -2,6 +2,14 @@
 # -*- coding: utf-8 -*-
 #This file is part of Tryton.  The COPYRIGHT file at the top level of
 #this repository contains the full copyright notices and license terms.
+import sys
+try:
+    import cdecimal
+    if 'decimal' not in sys.modules:
+        sys.modules['decimal'] = cdecimal
+except ImportError:
+    import decimal
+    sys.modules['cdecimal'] = decimal
 import unittest
 from decimal import Decimal
 import datetime
diff --git a/trytond/tests/test_fields.py b/trytond/tests/test_fields.py
index cf1705e39e..b068a7a121 100644
--- a/trytond/tests/test_fields.py
+++ b/trytond/tests/test_fields.py
@@ -2,6 +2,14 @@
 # -*- coding: utf-8 -*-
 #This file is part of Tryton.  The COPYRIGHT file at the top level of
 #this repository contains the full copyright notices and license terms.
+import sys
+try:
+    import cdecimal
+    if 'decimal' not in sys.modules:
+        sys.modules['decimal'] = cdecimal
+except ImportError:
+    import decimal
+    sys.modules['cdecimal'] = decimal
 import unittest
 import datetime
 from decimal import Decimal