diff --git a/setup.py b/setup.py
index 59b468f8c93..bd3e5ae52e7 100644
--- a/setup.py
+++ b/setup.py
@@ -169,7 +169,7 @@ def write_to_python_file(cls, path: str) -> None:
 # set to a non-empty value, the build type is Debug. Otherwise, the build type
 # is Release.
 def get_build_type(is_debug=None) -> str:
-    debug = int(os.environ.get("DEBUG", 0)) if is_debug is None else is_debug
+    debug = int(os.environ.get("DEBUG", 0) or 0) if is_debug is None else is_debug
     cfg = "Debug" if debug else "Release"
     return cfg