Index: include/llvm/LTO/LTOCodeGenerator.h
===================================================================
--- include/llvm/LTO/LTOCodeGenerator.h
+++ include/llvm/LTO/LTOCodeGenerator.h
@@ -148,6 +148,8 @@
 
   LLVMContext &getContext() { return Context; }
 
+  void resetMergedModule() { MergedModule.reset(); }
+
 private:
   void initializeLTOPasses();
 
Index: tools/lto/lto.cpp
===================================================================
--- tools/lto/lto.cpp
+++ tools/lto/lto.cpp
@@ -124,6 +124,11 @@
       : LTOCodeGenerator(*Context), OwnedContext(std::move(Context)) {
     setDiagnosticHandler(handleLibLTODiagnostic, nullptr); }
 
+  // Reset the module first in case MergedModule is created in OwnedContext.
+  // Module must be destructed before its context gets destructed.
+  ~LibLTOCodeGenerator() {
+    resetMergedModule(); }
+
   std::unique_ptr<MemoryBuffer> NativeObjectFile;
   std::unique_ptr<LLVMContext> OwnedContext;
 };