diff --git a/robotpy_build/autowrap/cxxparser.py b/robotpy_build/autowrap/cxxparser.py
index 3603a797..3bb7ad0e 100644
--- a/robotpy_build/autowrap/cxxparser.py
+++ b/robotpy_build/autowrap/cxxparser.py
@@ -1105,7 +1105,7 @@ def _on_class_method(
 
         # automatically retain references passed to constructors if the
         # user didn't specify their own keepalive
-        if is_constructor and not method_data.keepalive:
+        if is_constructor and method_data.keepalive is None:
             for i, pctx in enumerate(fctx.filtered_params):
                 if pctx.full_cpp_type.endswith("&"):
                     fctx.keepalives.append((1, i + 2))