diff --git a/build.py b/build.py
index 18fd028..c615f2b 100755
--- a/build.py
+++ b/build.py
@@ -1,7 +1,9 @@
 #! /usr/bin/env -S python3 -B
 
+import sys
+
 from rwx.prj.sphinx import SphinxProject
 
 
 if __name__ == "__main__":
-    return SphinxProject(__file__).build()
+    sys.exit(SphinxProject(__file__).build())