diff --git a/llvm/lib/LTO/LTO.cpp b/llvm/lib/LTO/LTO.cpp
--- a/llvm/lib/LTO/LTO.cpp
+++ b/llvm/lib/LTO/LTO.cpp
@@ -1216,6 +1216,14 @@
       MapVector<StringRef, BitcodeModule> &ModuleMap) {
     auto RunThinBackend = [&](AddStreamFn AddStream) {
       LTOLLVMContext BackendContext(Conf);
+
+      // Don't leave the decision to use opaque pointers to the reader as we
+      // may be mixing bitcode using opaque and typed pointers and we can
+      // only upgrade typed pointers to opaque pointers.
+      if (!BackendContext.hasSetOpaquePointersValue()) {
+        BackendContext.setOpaquePointers(true);
+      }
+
       Expected<std::unique_ptr<Module>> MOrErr = BM.parseModule(BackendContext);
       if (!MOrErr)
         return MOrErr.takeError();
diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -419,6 +419,14 @@
         CodegenThreadPool.async(
             [&](const SmallString<0> &BC, unsigned ThreadId) {
               LTOLLVMContext Ctx(C);
+
+              // Don't leave the decision to use opaque pointers to the reader
+              // as we may be mixing bitcode using opaque and typed pointers and
+              // we can only upgrade typed pointers to opaque pointers.
+              if (!Ctx.hasSetOpaquePointersValue()) {
+                Ctx.setOpaquePointers(true);
+              }
+
               Expected<std::unique_ptr<Module>> MOrErr = parseBitcodeFile(
                   MemoryBufferRef(StringRef(BC.data(), BC.size()), "ld-temp.o"),
                   Ctx);