Index: lib/CodeGen/CodeGenModule.cpp
===================================================================
--- lib/CodeGen/CodeGenModule.cpp
+++ lib/CodeGen/CodeGenModule.cpp
@@ -4235,8 +4235,8 @@
     case LangOptions::CoreFoundationABI::Swift: LLVM_FALLTHROUGH;
     case LangOptions::CoreFoundationABI::Swift5_0:
       CFConstantStringClassName =
-          Triple.isOSDarwin() ? "$s15SwiftFoundation19_NSCFConstantStringCN"
-                              : "$s10Foundation19_NSCFConstantStringCN";
+          Triple.isOSDarwin() ? "$s19SwiftFoundationBase19_NSCFConstantStringCN"
+                              : "$s14FoundationBase19_NSCFConstantStringCN";
       Ty = IntPtrTy;
       break;
     case LangOptions::CoreFoundationABI::Swift4_2: