diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 128de28..5c16782 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -838,8 +838,8 @@
           : Input.isSystem() ? SrcMgr::C_System : SrcMgr::C_User;
 
   if (Input.isBuffer()) {
-    SourceMgr.setMainFileID(SourceMgr.createFileID(
-        std::unique_ptr<llvm::MemoryBuffer>(Input.getBuffer()), Kind));
+    SourceMgr.setMainFileID(SourceMgr.createFileID(SourceManager::Unowned,
+                                                   Input.getBuffer(), Kind));
     assert(SourceMgr.getMainFileID().isValid() &&
            "Couldn't establish MainFileID!");
     return true;