diff --git a/_doctest_environment.py b/_doctest_environment.py
new file mode 100644
index 0000000..15f94df
--- /dev/null
+++ b/_doctest_environment.py
@@ -0,0 +1,7 @@
+# Toplevel for doctesting with passagemath
+
+from sage.all__sagemath_combinat import *
+from sage.all__sagemath_modules import *
+
+from k_combinat_for_sage.all import *
+from k_combinat_for_sage.all import _is_sequence
diff --git a/k_combinat_for_sage/all.py b/k_combinat_for_sage/all.py
index fe6c7b8..ee1694f 100644
--- a/k_combinat_for_sage/all.py
+++ b/k_combinat_for_sage/all.py
@@ -20,7 +20,11 @@
 #*****************************************************************************
 import sys
 
-from sage.all import *
+try:
+    from sage.all import *
+except ImportError:
+    from sage.all__sagemath_combinat import *
+
 from sage.combinat.partition_shifting_algebras import ShiftingOperatorAlgebra as ShiftingOperatorAlgebraExplicit
 
 parent_module = sys.modules['.'.join(__name__.split('.')[:-1]) or '__main__']
diff --git a/k_combinat_for_sage/core.py b/k_combinat_for_sage/core.py
index b4aa2fe..d72f0a3 100644
--- a/k_combinat_for_sage/core.py
+++ b/k_combinat_for_sage/core.py
@@ -13,7 +13,11 @@
 #                  http://www.gnu.org/licenses/
 #*****************************************************************************
 
-from sage.all import *
+try:
+    from sage.all import *
+except ImportError:
+    from sage.all__sagemath_combinat import *
+    from sage.all__sagemath_modules import *
 # ^*^ sphinx insert ^*^
 
 
diff --git a/k_combinat_for_sage/k_shape.py b/k_combinat_for_sage/k_shape.py
index ebcc248..b4bd244 100644
--- a/k_combinat_for_sage/k_shape.py
+++ b/k_combinat_for_sage/k_shape.py
@@ -20,7 +20,11 @@
 
 import sys
 
-from sage.all import *
+try:
+    from sage.all import *
+except ImportError:
+    from sage.all__sagemath_combinat import *
+    from sage.all__sagemath_modules import *
 
 parent_module = sys.modules['.'.join(__name__.split('.')[:-1]) or '__main__']
 if __name__ == '__main__' or parent_module.__name__ == '__main__':
diff --git a/k_combinat_for_sage/partition.py b/k_combinat_for_sage/partition.py
index 49dbf85..eab25b9 100644
--- a/k_combinat_for_sage/partition.py
+++ b/k_combinat_for_sage/partition.py
@@ -14,7 +14,12 @@
 #                  http://www.gnu.org/licenses/
 #*****************************************************************************
 
-from sage.all import *
+try:
+    from sage.all import *
+except ImportError:
+    from sage.all__sagemath_combinat import *
+    from sage.all__sagemath_modules import *
+
 # ^*^ sphinx insert ^*^
 
 # HELPERS
diff --git a/k_combinat_for_sage/proof_of_work.py b/k_combinat_for_sage/proof_of_work.py
index 3c6cad1..9620130 100755
--- a/k_combinat_for_sage/proof_of_work.py
+++ b/k_combinat_for_sage/proof_of_work.py
@@ -1,8 +1,7 @@
 #!/usr/bin/env sage
 # -*- coding: utf-8 -*-
 """ This file demonstrates that I have completed each requested task (or the functionality already existed in sage) by showing an example for each one. """
-from sage.all import *
-from all import *
+from .all import *
 print('Sage loaded.  Executing proof of work...')
 
 
diff --git a/k_combinat_for_sage/root_ideal.py b/k_combinat_for_sage/root_ideal.py
index b82ed18..d6b4db5 100644
--- a/k_combinat_for_sage/root_ideal.py
+++ b/k_combinat_for_sage/root_ideal.py
@@ -21,7 +21,11 @@
 
 import sys
 
-from sage.all import *
+try:
+    from sage.all import *
+except ImportError:
+    from sage.all__sagemath_combinat import *
+    from sage.all__sagemath_modules import *
 
 parent_module = sys.modules['.'.join(__name__.split('.')[:-1]) or '__main__']
 if __name__ == '__main__' or parent_module.__name__ == '__main__':
diff --git a/k_combinat_for_sage/shorthands.py b/k_combinat_for_sage/shorthands.py
index 9b76c5c..64800d4 100644
--- a/k_combinat_for_sage/shorthands.py
+++ b/k_combinat_for_sage/shorthands.py
@@ -3,7 +3,7 @@
 	from k_combinat_for_sage.shorthands import *
 
 """
-from all import *
+from .all import *
 # ^*^ sphinx insert ^*^
 
 # pre-initialized useful variables
diff --git a/k_combinat_for_sage/skew_partition.py b/k_combinat_for_sage/skew_partition.py
index 5750f02..9d4839f 100644
--- a/k_combinat_for_sage/skew_partition.py
+++ b/k_combinat_for_sage/skew_partition.py
@@ -20,7 +20,11 @@
 
 import sys
 
-from sage.all import *
+try:
+    from sage.all import *
+except ImportError:
+    from sage.all__sagemath_combinat import *
+    from sage.all__sagemath_modules import *
 
 parent_module = sys.modules['.'.join(__name__.split('.')[:-1]) or '__main__']
 if __name__ == '__main__' or parent_module.__name__ == '__main__':
diff --git a/k_combinat_for_sage/strong_marked_tableau.py b/k_combinat_for_sage/strong_marked_tableau.py
index b5bcaa6..d8eb8f6 100644
--- a/k_combinat_for_sage/strong_marked_tableau.py
+++ b/k_combinat_for_sage/strong_marked_tableau.py
@@ -20,7 +20,11 @@
 
 import sys
 
-from sage.all import *
+try:
+    from sage.all import *
+except ImportError:
+    from sage.all__sagemath_combinat import *
+    from sage.all__sagemath_modules import *
 
 parent_module = sys.modules['.'.join(__name__.split('.')[:-1]) or '__main__']
 if __name__ == '__main__' or parent_module.__name__ == '__main__':
diff --git a/k_combinat_for_sage/test_all.py b/k_combinat_for_sage/test_all.py
index 82216d8..6256d46 100755
--- a/k_combinat_for_sage/test_all.py
+++ b/k_combinat_for_sage/test_all.py
@@ -4,12 +4,17 @@
 # from __future__ import print_function
 import time
 
-from sage.all import *
+try:
+    from sage.all import *
+except ImportError:
+    from sage.all__sagemath_combinat import *
+    from sage.all__sagemath_modules import *
+
 print('Sage loaded.  Now loading local modules...')
-from testing import *
-from all import *
-from all import _is_sequence
-from strong_marked_tableau import __go_to_ribbon_head
+from .testing import *
+from .all import *
+from .all import _is_sequence
+from .strong_marked_tableau import __go_to_ribbon_head
 start_time = time.time()
 print('Modules loaded.  Testing...')
 
diff --git a/k_combinat_for_sage/testing.py b/k_combinat_for_sage/testing.py
index e4a42c1..1bf5e2d 100644
--- a/k_combinat_for_sage/testing.py
+++ b/k_combinat_for_sage/testing.py
@@ -1,5 +1,10 @@
 # Tools for testing purposes.
-from sage.all import *
+try:
+    from sage.all import *
+except ImportError:
+    from sage.all__sagemath_combinat import *
+    from sage.all__sagemath_modules import *
+
 
 def is_False_or_None(x):
 	return x is None or x == False
diff --git a/setup.py b/setup.py
index e38d9e9..30f1ac4 100644
--- a/setup.py
+++ b/setup.py
@@ -20,4 +20,10 @@
 	download_url=download_url,
 	keywords=['morse', 'k-boundary', 'k-rim', 'k-shape', 'skew-linked diagram', 'k-irreducible', 'root ideals', 'k-schur', 'combinatorics', 'sage', 'sagemath', 'raising root operators', 'catalan functions'],
 	classifiers=[],
+    extras_require={
+        'passagemath': ['passagemath-combinat',
+                        'passagemath-modules',
+                        'passagemath-repl',
+                        ],
+    },
 )
diff --git a/tox.ini b/tox.ini
new file mode 100644
index 0000000..7c69d7c
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,19 @@
+# tox -c tox-passagemath.ini
+[tox]
+envlist = passagemath
+
+[testenv:.pkg]
+passenv =
+    CPATH
+    LIBRARY_PATH
+
+[testenv:passagemath]
+usedevelop = True
+extras = passagemath
+
+setenv =
+    # For access to _doctest_environment.py
+    PYTHONPATH=.
+
+commands =
+    sage -tp --environment=_doctest_environment k_combinat_for_sage