diff --git a/interfaces/cython/cantera/test/test_onedim.py b/interfaces/cython/cantera/test/test_onedim.py
index 110ed013e..9a89f6a3b 100644
--- a/interfaces/cython/cantera/test/test_onedim.py
+++ b/interfaces/cython/cantera/test/test_onedim.py
@@ -241,7 +241,7 @@ class TestFreeFlame(utilities.CanteraTest):
 
         self.create_sim(p, Tin, reactants)
         self.solve_fixed_T()
-        filename = 'onedim-fixed-T.xml'
+        filename = 'onedim-fixed-T{0}.xml'.format(utilities.python_version)
         if os.path.exists(filename):
             os.remove(filename)
 
@@ -302,7 +302,7 @@ class TestFreeFlame(utilities.CanteraTest):
         p = 2 * ct.one_atm
         Tin = 400
 
-        filename = 'onedim-add-species.xml'
+        filename = 'onedim-add-species{0}.xml'.format(utilities.python_version)
         if os.path.exists(filename):
             os.remove(filename)
 
@@ -330,7 +330,7 @@ class TestFreeFlame(utilities.CanteraTest):
         p = 2 * ct.one_atm
         Tin = 400
 
-        filename = 'onedim-add-species.xml'
+        filename = 'onedim-add-species{0}.xml'.format(utilities.python_version)
         if os.path.exists(filename):
             os.remove(filename)
 
diff --git a/interfaces/cython/cantera/test/utilities.py b/interfaces/cython/cantera/test/utilities.py
index cb705ba5e..8a53ff6a7 100644
--- a/interfaces/cython/cantera/test/utilities.py
+++ b/interfaces/cython/cantera/test/utilities.py
@@ -4,6 +4,8 @@ import os
 import warnings
 
 _ver = sys.version_info[:2]
+python_version = str(_ver[0])
+
 if  _ver < (2,7) or (3,0) <= _ver < (3,2):
     # unittest2 is a backport of the new features added to the unittest
     # testing framework in Python 2.7 and Python 3.2. See