diff --git a/llvm/include/llvm/Support/VirtualFileSystem.h b/llvm/include/llvm/Support/VirtualFileSystem.h
--- a/llvm/include/llvm/Support/VirtualFileSystem.h
+++ b/llvm/include/llvm/Support/VirtualFileSystem.h
@@ -652,7 +652,7 @@
   friend class RedirectingFileSystemParser;
 
   bool shouldUseExternalFS() const {
-    return ExternalFSValidWD && IsFallthrough;
+    return IsFallthrough;
   }
 
   // In a RedirectingFileSystem, keys can be specified in Posix or Windows
@@ -672,9 +672,6 @@
   /// The current working directory of the file system.
   std::string WorkingDirectory;
 
-  /// Whether the current working directory is valid for the external FS.
-  bool ExternalFSValidWD = false;
-
   /// The file system to use for external references.
   IntrusiveRefCntPtr<FileSystem> ExternalFS;
 
diff --git a/llvm/lib/Support/VirtualFileSystem.cpp b/llvm/lib/Support/VirtualFileSystem.cpp
--- a/llvm/lib/Support/VirtualFileSystem.cpp
+++ b/llvm/lib/Support/VirtualFileSystem.cpp
@@ -1016,7 +1016,6 @@
     if (auto ExternalWorkingDirectory =
             ExternalFS->getCurrentWorkingDirectory()) {
       WorkingDirectory = *ExternalWorkingDirectory;
-      ExternalFSValidWD = true;
     }
 }
 
@@ -1076,10 +1075,8 @@
     return errc::no_such_file_or_directory;
 
   // Always change the external FS but ignore its result.
-  if (ExternalFS) {
-    auto EC = ExternalFS->setCurrentWorkingDirectory(Path);
-    ExternalFSValidWD = !static_cast<bool>(EC);
-  }
+  if (ExternalFS)
+    ExternalFS->setCurrentWorkingDirectory(Path);
 
   SmallString<128> AbsolutePath;
   Path.toVector(AbsolutePath);