diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
@@ -174,7 +174,8 @@
     Scanned = true;
 
     // Create a compiler instance to handle the actual work.
-    CompilerInstance ScanInstance(std::move(PCHContainerOps));
+    ScanInstanceStorage.emplace(std::move(PCHContainerOps));
+    CompilerInstance &ScanInstance = *ScanInstanceStorage;
     ScanInstance.setInvocation(std::move(Invocation));
 
     // Create the compiler's actual diagnostics engine.
@@ -304,7 +305,8 @@
   bool OptimizeArgs;
   bool EagerLoadModules;
   bool DisableFree;
-  llvm::Optional<StringRef> ModuleName;
+  Optional<StringRef> ModuleName;
+  Optional<CompilerInstance> ScanInstanceStorage;
   std::shared_ptr<ModuleDepCollector> MDC;
   std::vector<std::string> LastCC1Arguments;
   bool Scanned = false;