diff --git a/Cantera/python/Cantera/__init__.py b/Cantera/python/Cantera/__init__.py
index 1f05f195a..8fc7ba34b 100755
--- a/Cantera/python/Cantera/__init__.py
+++ b/Cantera/python/Cantera/__init__.py
@@ -12,6 +12,14 @@ from gases import *
 from set import set
 from importFromFile import *
 
+import os as _os
+import sys as _sys
+
+if not os.getenv('PYTHON_CMD'):
+    # Setting PYTHON_CMD here avoids issues with .cti -> .xml conversions
+    # in cases where the python interpreter isn't in the system path.
+    os.environ['PYTHON_CMD'] = _sys.executable
+
 def writeCSV(f, list):
     """
     Write list items to file 'f' in
diff --git a/Cantera/src/base/ct2ctml.cpp b/Cantera/src/base/ct2ctml.cpp
index 591d599fb..4064ed126 100644
--- a/Cantera/src/base/ct2ctml.cpp
+++ b/Cantera/src/base/ct2ctml.cpp
@@ -64,7 +64,7 @@ namespace ctml {
     if (!py) {
       const char* hm = getenv("HOME");
       string home = stripws(string(hm));
-      string cmd = string("source ")+home
+      string cmd = string(". ")+home
 	+string("/setup_cantera &> /dev/null");
       system(cmd.c_str());
       py = getenv("PYTHON_CMD");