diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 54eef40..28c5af5 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -4913,6 +4913,10 @@
     // cv-qualifiers on class members don't affect default ctor / dtor calls.
     if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor)
       Quals = 0;
+    // cv-qualifiers on class members affect the type of both '*this' and the
+    // argument for an assignment.
+    if (IsAssignment)
+      TQ |= Quals;
     return S.LookupSpecialMember(Class, CSM,
                                  ConstArg || (Quals & Qualifiers::Const),
                                  VolatileArg || (Quals & Qualifiers::Volatile),