diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 566edb0..d9e3226 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -928,6 +928,9 @@
   // Adjust target options based on codegen options.
   getTarget().adjustTargetOptions(getCodeGenOpts(), getTargetOpts());
 
+  if (auto *Aux = getAuxTarget())
+    getTarget().setAuxTarget(Aux);
+
   // rewriter project will change target built-in bool type from its default.
   if (getFrontendOpts().ProgramAction == frontend::RewriteObjC)
     getTarget().noSignedCharForObjCBool();