diff --git a/build.py b/build.py
index d9a9f6d..ad17832 100644
--- a/build.py
+++ b/build.py
@@ -1,7 +1,7 @@
 import warnings
 import subprocess
 
-res = subprocess.run(["python3", "setup.py", "build_ext", "--inplace"])
+res = subprocess.run(["python3", "setup.py", "build_ext", "--inplace"], cwd="./tdcgal")
 if res.returncode != 0:
     warnings.warn(res.stderr.decode())
     warnings.warn("Error building toydesigner-cgal")