diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index a243b2c..76c64f4 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -1113,7 +1113,9 @@
   if (SCS.CopyConstructor) {
     // FIXME: When can ToType be a reference type?
     assert(!ToType->isReferenceType());
-
+    if (SCS.Second == ICK_Derived_To_Base)
+      ImpCastExprToType(From, ToType, CastExpr::CK_DerivedToBase,
+                        /*isLvalue=*/true);
     OwningExprResult FromResult =
       BuildCXXConstructExpr(/*FIXME:ConstructLoc*/SourceLocation(),
                             ToType, SCS.CopyConstructor,