diff --git a/clang/include/clang/Basic/FileSystemStatCache.h b/clang/include/clang/Basic/FileSystemStatCache.h
index 2e9528db915c..af2535661e5a 100644
--- a/clang/include/clang/Basic/FileSystemStatCache.h
+++ b/clang/include/clang/Basic/FileSystemStatCache.h
@@ -38,6 +38,10 @@ struct FileData {
   bool IsDirectory;
   bool IsNamedPipe;
   bool InPCH;
+  bool IsVFSMapped; // FIXME: remove this when files support multiple names
+  FileData()
+      : Size(0), ModTime(0), IsDirectory(false), IsNamedPipe(false),
+        InPCH(false), IsVFSMapped(false) {}
 };
 
 /// \brief Abstract interface for introducing a FileManager cache for 'stat'
diff --git a/clang/include/clang/Basic/VirtualFileSystem.h b/clang/include/clang/Basic/VirtualFileSystem.h
index 978e0408daf1..0a9949612c03 100644
--- a/clang/include/clang/Basic/VirtualFileSystem.h
+++ b/clang/include/clang/Basic/VirtualFileSystem.h
@@ -39,6 +39,9 @@ class Status {
   llvm::sys::fs::file_type Type;
   llvm::sys::fs::perms Perms;
 
+public:
+  bool IsVFSMapped; // FIXME: remove when files support multiple names
+
 public:
   Status() : Type(llvm::sys::fs::file_type::status_error) {}
   Status(const llvm::sys::fs::file_status &Status);
diff --git a/clang/lib/Basic/FileManager.cpp b/clang/lib/Basic/FileManager.cpp
index 940fcaf4174d..14731f6b09cd 100644
--- a/clang/lib/Basic/FileManager.cpp
+++ b/clang/lib/Basic/FileManager.cpp
@@ -274,6 +274,16 @@ const FileEntry *FileManager::getFile(StringRef Filename, bool openFile,
 
   NamedFileEnt.setValue(&UFE);
   if (UFE.isValid()) { // Already have an entry with this inode, return it.
+
+    // FIXME: this hack ensures that if we look up a file by a virtual path in
+    // the VFS that the getDir() will have the virtual path, even if we found
+    // the file by a 'real' path first. This is required in order to find a
+    // module's structure when its headers/module map are mapped in the VFS.
+    // We should remove this as soon as we can properly support a file having
+    // multiple names.
+    if (DirInfo != UFE.Dir && Data.IsVFSMapped)
+      UFE.Dir = DirInfo;
+
     // If the stat process opened the file, close it to avoid a FD leak.
     if (F)
       delete F;
diff --git a/clang/lib/Basic/FileSystemStatCache.cpp b/clang/lib/Basic/FileSystemStatCache.cpp
index 44ba48aa2fcc..0f16e94a05ec 100644
--- a/clang/lib/Basic/FileSystemStatCache.cpp
+++ b/clang/lib/Basic/FileSystemStatCache.cpp
@@ -39,6 +39,7 @@ static void copyStatusToFileData(const vfs::Status &Status,
   Data.IsDirectory = Status.isDirectory();
   Data.IsNamedPipe = Status.getType() == llvm::sys::fs::file_type::fifo_file;
   Data.InPCH = false;
+  Data.IsVFSMapped = Status.IsVFSMapped;
 }
 
 /// FileSystemStatCache::get - Get the 'stat' information for the specified
diff --git a/clang/lib/Basic/VirtualFileSystem.cpp b/clang/lib/Basic/VirtualFileSystem.cpp
index c89b071a773e..a469c9abc392 100644
--- a/clang/lib/Basic/VirtualFileSystem.cpp
+++ b/clang/lib/Basic/VirtualFileSystem.cpp
@@ -31,13 +31,13 @@ using llvm::sys::fs::UniqueID;
 Status::Status(const file_status &Status)
     : UID(Status.getUniqueID()), MTime(Status.getLastModificationTime()),
       User(Status.getUser()), Group(Status.getGroup()), Size(Status.getSize()),
-      Type(Status.type()), Perms(Status.permissions()) {}
+      Type(Status.type()), Perms(Status.permissions()), IsVFSMapped(false)  {}
 
 Status::Status(StringRef Name, StringRef ExternalName, UniqueID UID,
                sys::TimeValue MTime, uint32_t User, uint32_t Group,
                uint64_t Size, file_type Type, perms Perms)
     : Name(Name), UID(UID), MTime(MTime), User(User), Group(Group), Size(Size),
-      Type(Type), Perms(Perms) {}
+      Type(Type), Perms(Perms), IsVFSMapped(false) {}
 
 bool Status::equivalent(const Status &Other) const {
   return getUniqueID() == Other.getUniqueID();
@@ -801,6 +801,8 @@ ErrorOr<Status> VFSFromYAML::status(const Twine &Path) {
     assert(!S || S->getName() == F->getExternalContentsPath());
     if (S && !F->useExternalName(UseExternalNames))
       S->setName(PathStr);
+    if (S)
+      S->IsVFSMapped = true;
     return S;
   } else { // directory
     DirectoryEntry *DE = cast<DirectoryEntry>(*Result);
diff --git a/clang/test/VFS/Inputs/actual_module.map b/clang/test/VFS/Inputs/actual_module.map
index 282dac37c7b0..d2f5b64a38d3 100644
--- a/clang/test/VFS/Inputs/actual_module.map
+++ b/clang/test/VFS/Inputs/actual_module.map
@@ -2,3 +2,7 @@ module not_real {
   header "not_real.h"
   export *
 }
+module import_some_frame {
+  header "import_some_frame.h"
+  export *
+}
diff --git a/clang/test/VFS/Inputs/import_some_frame.h b/clang/test/VFS/Inputs/import_some_frame.h
new file mode 100644
index 000000000000..c1f68c83fc58
--- /dev/null
+++ b/clang/test/VFS/Inputs/import_some_frame.h
@@ -0,0 +1,2 @@
+#import <SomeFramework/public_header.h>
+#import <SomeFramework/public_header2.h>
diff --git a/clang/test/VFS/Inputs/public_header.h b/clang/test/VFS/Inputs/public_header.h
index 471107762b15..09d9969d319d 100644
--- a/clang/test/VFS/Inputs/public_header.h
+++ b/clang/test/VFS/Inputs/public_header.h
@@ -1 +1,2 @@
+#import <SomeFramework/public_header2.h>
 void from_framework(void);
diff --git a/clang/test/VFS/Inputs/public_header2.h b/clang/test/VFS/Inputs/public_header2.h
new file mode 100644
index 000000000000..d883613ac120
--- /dev/null
+++ b/clang/test/VFS/Inputs/public_header2.h
@@ -0,0 +1 @@
+// public_header2.h
diff --git a/clang/test/VFS/Inputs/some_frame_module.map b/clang/test/VFS/Inputs/some_frame_module.map
new file mode 100644
index 000000000000..3ce59b254d83
--- /dev/null
+++ b/clang/test/VFS/Inputs/some_frame_module.map
@@ -0,0 +1,5 @@
+framework module SomeFramework {
+  umbrella header "public_header.h"
+  export *
+  module * { export * }
+}
diff --git a/clang/test/VFS/Inputs/vfsoverlay.yaml b/clang/test/VFS/Inputs/vfsoverlay.yaml
index 5c1380870d57..0aa8cd619a5f 100644
--- a/clang/test/VFS/Inputs/vfsoverlay.yaml
+++ b/clang/test/VFS/Inputs/vfsoverlay.yaml
@@ -6,14 +6,26 @@
         { 'name': 'not_real.h', 'type': 'file',
           'external-contents': 'INPUT_DIR/actual_header.h'
         },
+        { 'name': 'import_some_frame.h', 'type': 'file',
+          'external-contents': 'INPUT_DIR/import_some_frame.h'
+        },
         { 'name': 'module.map', 'type': 'file',
           'external-contents': 'INPUT_DIR/actual_module.map'
         },
         { 'name': 'include_real.h', 'type': 'file',
           'external-contents': 'INPUT_DIR/include_real.h'
         },
-        { 'name': 'SomeFramework.framework/Headers/public_header.h', 'type': 'file',
-          'external-contents': 'INPUT_DIR/public_header.h'
+        { 'name': 'SomeFramework.framework', 'type': 'directory',
+          'contents': [
+            { 'name': 'Headers', 'type': 'directory',
+              'contents': [
+                { 'name': 'public_header.h', 'type': 'file',
+                  'external-contents': 'INPUT_DIR/public_header.h' },
+                { 'name': 'public_header2.h', 'type': 'file',
+                  'external-contents': 'INPUT_DIR/public_header2.h' }
+              ]
+            }
+          ]
         },
         { 'name': 'Foo.framework/Headers/Foo.h', 'type': 'file',
           'external-contents': 'INPUT_DIR/Foo.h'
diff --git a/clang/test/VFS/real-path-found-first.m b/clang/test/VFS/real-path-found-first.m
new file mode 100644
index 000000000000..f494c6eb1534
--- /dev/null
+++ b/clang/test/VFS/real-path-found-first.m
@@ -0,0 +1,74 @@
+// This test is for cases where we lookup a file by its 'real' path before we
+// use its VFS-mapped path. If we accidentally use the real path in header
+// search, we will not find a module for the headers.  To test that we
+// intentionally rebuild modules, since the precompiled module file refers to
+// the dependency files by real path.
+
+// REQUIRES: shell
+// RUN: rm -rf %t %t-cache %t.pch
+// RUN: mkdir -p %t/SomeFramework.framework/Modules
+// RUN: cp %S/Inputs/some_frame_module.map %t/SomeFramework.framework/Modules/module.modulemap
+// RUN: sed -e "s:INPUT_DIR:%S/Inputs:g" -e "s:OUT_DIR:%t:g" %S/Inputs/vfsoverlay.yaml > %t.yaml
+
+// Build
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t-cache -F %t \
+// RUN:     -ivfsoverlay %t.yaml -fsyntax-only %s -verify -Wauto-import \
+// RUN:     -Werror=non-modular-include-in-framework-module
+
+// Rebuild
+// RUN: echo ' ' >> %t/SomeFramework.framework/Modules/module.modulemap
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t-cache -F %t \
+// RUN:     -ivfsoverlay %t.yaml -fsyntax-only %s -verify -Wauto-import \
+// RUN:     -Werror=non-modular-include-in-framework-module
+
+// Load from PCH
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t-cache -F %t \
+// RUN:     -ivfsoverlay %t.yaml -emit-pch  %s -o %t.pch \
+// RUN:     -Werror=non-modular-include-in-framework-module \
+// RUN:     -fmodules-ignore-macro=WITH_PREFIX
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t-cache -F %t \
+// RUN:     -ivfsoverlay %t.yaml -include-pch %t.pch -fsyntax-only  %s \
+// RUN:     -Werror=non-modular-include-in-framework-module -DWITH_PREFIX \
+// RUN:     -fmodules-ignore-macro=WITH_PREFIX
+
+// While indexing
+// RUN: c-index-test -index-file %s -fmodules -fmodules-cache-path=%t-cache -F %t \
+// RUN:     -ivfsoverlay %t.yaml -fsyntax-only -Wauto-import \
+// RUN:     -Werror=non-modular-include-in-framework-module | FileCheck %s
+// RUN: echo ' ' >> %t/SomeFramework.framework/Modules/module.modulemap
+// RUN: c-index-test -index-file %s -fmodules -fmodules-cache-path=%t-cache -F %t \
+// RUN:     -ivfsoverlay %t.yaml -fsyntax-only -Wauto-import \
+// RUN:     -Werror=non-modular-include-in-framework-module | FileCheck %s
+// CHECK: warning: treating
+// CHECK-NOT: error
+
+// With a VFS-mapped module map file
+// RUN: mv %t/SomeFramework.framework/Modules/module.modulemap %t/hide_module.map
+// RUN: echo "{ 'version': 0, 'roots': [ { " > %t2.yaml
+// RUN: echo "'name': '%t/SomeFramework.framework/Modules/module.modulemap'," >> %t2.yaml
+// RUN: echo "'type': 'file', 'external-contents': '%t/hide_module.map' } ] }" >> %t2.yaml
+
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t-cache -F %t \
+// RUN:     -ivfsoverlay %t.yaml -ivfsoverlay %t2.yaml -fsyntax-only %s -verify \
+// RUN:     -Wauto-import -Werror=non-modular-include-in-framework-module
+// RUN: echo ' ' >> %t/hide_module.map
+// RUN: %clang_cc1 -fmodules -fmodules-cache-path=%t-cache -F %t \
+// RUN:     -ivfsoverlay %t.yaml -ivfsoverlay %t2.yaml -fsyntax-only %s -verify \
+// RUN:     -Wauto-import -Werror=non-modular-include-in-framework-module
+
+// Within a module build
+// RUN: echo '@import import_some_frame;' | \
+// RUN:   %clang_cc1 -fmodules -fmodules-cache-path=%t-cache -F %t \
+// RUN:      -ivfsoverlay %t.yaml -ivfsoverlay %t2.yaml -fsyntax-only - \
+// RUN:      -Werror=non-modular-include-in-framework-module -x objective-c -I %t
+// RUN: echo ' ' >> %t/hide_module.map
+// RUN: echo '@import import_some_frame;' | \
+// RUN:   %clang_cc1 -fmodules -fmodules-cache-path=%t-cache -F %t \
+// RUN:      -ivfsoverlay %t.yaml -ivfsoverlay %t2.yaml -fsyntax-only - \
+// RUN:      -Werror=non-modular-include-in-framework-module -x objective-c -I %t
+
+#ifndef WITH_PREFIX
+#import <SomeFramework/public_header.h> // expected-warning{{treating}}
+#import <SomeFramework/public_header2.h> // expected-warning{{treating}}
+@import SomeFramework.public_header2;
+#endif