diff --git a/build.py b/build.py
index e42b0ca..dc034f1 100644
--- a/build.py
+++ b/build.py
@@ -265,7 +265,7 @@ def main():
             asyncio.run(name_substitution.do_substitution(
                 source_tree,
                 tarpath=None,
-                workers=os.cpu_count()
+                workers=min(32, os.cpu_count())
             ))
         else:
             print("Apply patches using quilt, then press Enter")