Index: llvm/include/llvm/Support/VirtualFileSystem.h
===================================================================
--- llvm/include/llvm/Support/VirtualFileSystem.h
+++ llvm/include/llvm/Support/VirtualFileSystem.h
@@ -650,6 +650,9 @@
   /// The root(s) of the virtual file system.
   std::vector<std::unique_ptr<Entry>> Roots;
 
+  /// The current working directory of the file system.
+  std::string WorkingDirectory;
+
   /// The file system to use for external references.
   IntrusiveRefCntPtr<FileSystem> ExternalFS;
 
Index: llvm/lib/Support/VirtualFileSystem.cpp
===================================================================
--- llvm/lib/Support/VirtualFileSystem.cpp
+++ llvm/lib/Support/VirtualFileSystem.cpp
@@ -1035,12 +1035,13 @@
 
 llvm::ErrorOr<std::string>
 RedirectingFileSystem::getCurrentWorkingDirectory() const {
-  return ExternalFS->getCurrentWorkingDirectory();
+  return WorkingDirectory;
 }
 
 std::error_code
 RedirectingFileSystem::setCurrentWorkingDirectory(const Twine &Path) {
-  return ExternalFS->setCurrentWorkingDirectory(Path);
+  WorkingDirectory = Path.str();
+  return {};
 }
 
 std::error_code RedirectingFileSystem::isLocal(const Twine &Path,
Index: llvm/unittests/Support/VirtualFileSystemTest.cpp
===================================================================
--- llvm/unittests/Support/VirtualFileSystemTest.cpp
+++ llvm/unittests/Support/VirtualFileSystemTest.cpp
@@ -1994,3 +1994,38 @@
   EXPECT_EQ(FS->getRealPath("/non_existing", RealPath),
             errc::no_such_file_or_directory);
 }
+
+TEST_F(VFSFromYAMLTest, WorkingDirectory) {
+  IntrusiveRefCntPtr<DummyFileSystem> Lower(new DummyFileSystem());
+  Lower->addDirectory("//root/");
+  Lower->addDirectory("//root/foo");
+  Lower->addRegularFile("//root/foo/a");
+  Lower->addRegularFile("//root/foo/b");
+  IntrusiveRefCntPtr<vfs::FileSystem> FS = getFromYAMLString(
+      "{ 'use-external-names': false,\n"
+      "  'roots': [\n"
+      "{\n"
+      "  'type': 'directory',\n"
+      "  'name': '//root/',\n"
+      "  'contents': [ {\n"
+      "                  'type': 'file',\n"
+      "                  'name': 'bar/a',\n"
+      "                  'external-contents': '//root/foo/a'\n"
+      "                }\n"
+      "              ]\n"
+      "}\n"
+      "]\n"
+      "}",
+      Lower);
+  ASSERT_TRUE(FS.get() != nullptr);
+  FS->setCurrentWorkingDirectory("//root/bar/");
+
+  llvm::ErrorOr<vfs::Status> Status = FS->status("./a");
+  ASSERT_FALSE(Status.getError());
+  EXPECT_TRUE(Status->isStatusKnown());
+  EXPECT_FALSE(Status->isDirectory());
+  EXPECT_TRUE(Status->isRegularFile());
+  EXPECT_FALSE(Status->isSymlink());
+  EXPECT_FALSE(Status->isOther());
+  EXPECT_TRUE(Status->exists());
+}