diff --git a/src/script_opt/Stmt.cc b/src/script_opt/Stmt.cc
index 9caf1cde83..7da1343361 100644
--- a/src/script_opt/Stmt.cc
+++ b/src/script_opt/Stmt.cc
@@ -951,7 +951,7 @@ void WhenInfo::UpdateIDs(Reducer* c)
 
 StmtPtr WhenStmt::Duplicate()
 	{
-	return SetSucc(new WhenStmt(wi));
+	return SetSucc(new WhenStmt(std::make_shared<WhenInfo>(wi.get())));
 	}
 
 bool WhenStmt::IsReduced(Reducer* c) const