diff --git a/SConstruct b/SConstruct
index 018a67fd0..058a9eea3 100644
--- a/SConstruct
+++ b/SConstruct
@@ -255,6 +255,11 @@ defaults.fsLayout = 'compact' if env['OS'] == 'Windows' else 'standard'
 defaults.env_vars = 'LD_LIBRARY_PATH' if 'LD_LIBRARY_PATH' in os.environ else ''
 defaults.python_prefix = '$prefix' if env['OS'] != 'Windows' else ''
 
+# Transform lists into strings to keep cantera.conf clean
+for key,value in defaults.__dict__.items():
+    if isinstance(value, (list, tuple)):
+        defaults.__dict__[key] = ' '.join(value)
+
 # **************************************
 # *** Read user-configurable options ***
 # **************************************