diff --git a/_doctest_environment.py b/_doctest_environment.py
new file mode 100644
index 0000000..6971085
--- /dev/null
+++ b/_doctest_environment.py
@@ -0,0 +1,3 @@
+# Toplevel for doctesting with passagemath
+
+from sage.all__sagemath_modules import *
diff --git a/setup.py b/setup.py
index 536994d..b63227f 100644
--- a/setup.py
+++ b/setup.py
@@ -38,4 +38,12 @@ def readfile(filename):
     setup_requires=['sage-package'],
     install_requires=['sage-package', 'networkx~=2.2'],
     python_requires='>=2.7',
+    extras_require={
+        'passagemath': [
+            'passagemath-combinat',
+            'passagemath-graphs',
+            'passagemath-modules',
+            'passagemath-repl',
+        ],
+    },
 )
diff --git a/tox.ini b/tox.ini
new file mode 100644
index 0000000..3821b8c
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,23 @@
+[tox]
+envlist = passagemath
+
+[testenv:.pkg]
+passenv =
+    CPATH
+    LIBRARY_PATH
+
+[testenv:passagemath]
+usedevelop = True
+extras = passagemath
+
+passenv =
+    CPATH
+    LIBRARY_PATH
+
+setenv =
+    # For access to _doctest_environment.py
+    PYTHONPATH=.
+
+commands =
+    python -c 'import arithmat'
+    sage -tp --force-lib --environment=_doctest_environment arithmat