diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
--- a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
+++ b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
@@ -55,6 +55,11 @@
   /// \returns True if the entry is valid.
   bool isValid() const { return !MaybeStat || MaybeStat->isStatusKnown(); }
 
+  /// \returns True if the current entry points to a directory.
+  bool isDirectory() const {
+    return MaybeStat && MaybeStat->isDirectory();
+  }
+
   /// \returns The error or the file's contents.
   llvm::ErrorOr<StringRef> getContents() const {
     if (!MaybeStat)
diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
@@ -176,6 +176,8 @@
   llvm::ErrorOr<StringRef> Contents = Entry->getContents();
   if (!Contents)
     return Contents.getError();
+  if (Entry->isDirectory())
+    return llvm::ErrorOr<std::unique_ptr<llvm::vfs::File>>(std::make_error_code(std::errc::is_a_directory));
   return std::make_unique<MinimizedVFSFile>(
       llvm::MemoryBuffer::getMemBuffer(*Contents, Entry->getName(),
                                        /*RequiresNullTerminator=*/false),
@@ -191,7 +193,7 @@
 
   // Check the local cache first.
   if (const CachedFileSystemEntry *Entry = getCachedEntry(Filename))
-    return createFile(Entry);
+    createFile(Entry);
 
   // FIXME: Handle PCM/PCH files.
   // FIXME: Handle module map files.