diff --git a/setup.py b/setup.py
index 801526e0..ccf96520 100644
--- a/setup.py
+++ b/setup.py
@@ -162,7 +162,7 @@ def run(self):
         super().run()
 
 
-distutils.command.build.build.sub_commands.append(("build_cosmosis", None))
+distutils.command.build.build.sub_commands.insert(0, ("build_cosmosis", None))
 
 requirements = [
     "pyyaml",