diff --git a/interfaces/python/setup.py.in b/interfaces/python/setup.py.in
index 8fda052d9..de3ebbb6b 100644
--- a/interfaces/python/setup.py.in
+++ b/interfaces/python/setup.py.in
@@ -18,7 +18,7 @@ if '@python_package@' == 'full':
           packages = ["","Cantera","Cantera.OneD",
                       "MixMaster","MixMaster.Units"],
           package_data = {'Cantera': dataFiles},
-          ext_modules=[Extension('_spam', ['../../src/python/spam.c'])])
+          ext_modules=[Extension('_spam', [@spam_source@])])
 
 elif '@python_package@' == 'minimal':
     setup(name="Cantera CTI File Processor",
diff --git a/src/python/SConscript b/src/python/SConscript
index b039766e9..0bc63fde1 100644
--- a/src/python/SConscript
+++ b/src/python/SConscript
@@ -19,6 +19,7 @@ for var in ('VS80COMNTOOLS', 'VS90COMNTOOLS', 'VS100COMNTOOLS'):
     if var in os.environ:
         localenv['ENV'][var] = os.environ[var]
 
+localenv['spam_source'] = repr(File('#src/python/spam.c').abspath)
 make_setup = localenv.SubstFile('#interfaces/python/setup.py',
                                 '#interfaces/python/setup.py.in')