diff --git a/src/element.cpp b/src/element.cpp
index 3ed14c9..ebc5763 100644
--- a/src/element.cpp
+++ b/src/element.cpp
@@ -35,7 +35,8 @@ shared_ptr<ValType> StructType::struct_replace(
 	shared_ptr<StructType> ut,
 	map<shared_ptr<TemplateType>, shared_ptr<TemplateType>>& eq) {
 	auto tt = make_shared<StructType>();
-	(*tt) = (*ut);
+	tt->str = str;
+	tt->mp = ut->mp;
 	set<shared_ptr<Struct>> vis;
 	for (auto u = str; u.get() != nullptr; u = u->fa.lock()) {
 		vis.insert(u);
diff --git a/tests/ok/simple-logic3.ac b/tests/ok/simple-logic3.ac
new file mode 100644
index 0000000..6795e16
--- /dev/null
+++ b/tests/ok/simple-logic3.ac
@@ -0,0 +1,32 @@
+struct
+{
+	struct A<x>()
+	{
+		struct AA<y>(){};
+		struct AB<y>()
+		{
+			struct ABA<z>()
+			{
+			};
+		};
+	};
+	struct B<x>()
+	{
+		struct BA<y>()
+		{
+			a = A<y>::AB<x>::ABA<y>();
+		};
+		struct BB<y>()
+		{
+			struct BBA<z>()
+			{
+			};
+			struct BBB<z>(p:z)
+			{
+				a = BA<z>();
+			};
+		};
+	};
+	struct C(delete){};
+	a = Fn<>()->A<C>::AB<B<C>>::ABA<C>{return B<B<C>>::BB<B<C>::BB<C>>::BBB<C>(admit<C>()).a.a;};
+}main;
\ No newline at end of file