diff --git a/cppwinrt/type_writers.h b/cppwinrt/type_writers.h
index ce8b095d6..3ef53bb71 100644
--- a/cppwinrt/type_writers.h
+++ b/cppwinrt/type_writers.h
@@ -129,7 +129,7 @@ namespace cppwinrt
             generic_param_guard(generic_param_guard&& other)
                 : owner(other.owner)
             {
-                owner = nullptr;
+                other.owner = nullptr;
             }
 
             generic_param_guard& operator=(generic_param_guard&& other)