diff --git a/setup.py b/setup.py
index dabb917..79cb561 100644
--- a/setup.py
+++ b/setup.py
@@ -182,7 +182,7 @@ def platform_config():
     ext_modules =  [
         Extension(
             "spidermonkey",
-            sources=find_sources(),
+            sources=sorted(find_sources()),
             **platform_config()
         )
     ],