diff --git a/std/typecons.d b/std/typecons.d
index 1252e6001..69c557980 100644
--- a/std/typecons.d
+++ b/std/typecons.d
@@ -2500,7 +2500,7 @@ if (!is(T == class))
             _store = cast(Impl*) enforce(malloc(Impl.sizeof));
             if (hasIndirections!T)
             {
-                GC.addRange(&_store._payload, Impl.sizeof);
+                GC.addRange(&_store._payload, T.sizeof);
             }
             emplace(&_store._payload, args);
             _store._count = 1;