diff --git a/.drone.yml b/.drone.yml
index 21be0a77d1..ae5d7bb111 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -1,4 +1,4 @@
 image: python2.7
 script:
   - pip install tox pydot
-  - tox
+  - tox -e py27
diff --git a/CHANGELOG b/CHANGELOG
index d24970094d..e27a6ebaca 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,4 @@
+* Add support for PyPy
 * Allow to provide extra keyword arguments to set_xmlrpc()
 * Add support of fields.TimeDelta
 * Remove password on set_trytond
diff --git a/setup.py b/setup.py
index 23cf6d839f..b7e9014b9c 100644
--- a/setup.py
+++ b/setup.py
@@ -58,6 +58,8 @@ setup(name=name,
         'GNU Library or Lesser General Public License (LGPL)',
         'Operating System :: OS Independent',
         'Programming Language :: Python :: 2.7',
+        'Programming Language :: Python :: Implementation :: CPython',
+        'Programming Language :: Python :: Implementation :: PyPy',
         'Topic :: Office/Business',
         ],
     platforms='any',
diff --git a/tox.ini b/tox.ini
index c40f069181..a25995ed12 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py27
+envlist = py27,pypy
 
 [testenv]
 commands = {envpython} setup.py test