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
@@ -1224,6 +1224,11 @@
             ExternalFS->getCurrentWorkingDirectory()) {
       WorkingDirectory = *ExternalWorkingDirectory;
     }
+  if (WorkingDirectory == "") {
+    SmallString<256> cwd;
+    llvm::sys::fs::current_path(cwd);
+    WorkingDirectory = std::string(cwd);
+  }
 }
 
 /// Directory iterator implementation for \c RedirectingFileSystem's
@@ -1927,7 +1932,7 @@
           EC = FS->makeAbsolute(FullPath, Name);
           Name = canonicalize(Name);
         } else {
-          EC = sys::fs::make_absolute(Name);
+          EC = FS->makeAbsolute(Name);
         }
         if (EC) {
           assert(NameValueNode && "Name presence should be checked earlier");
diff --git a/llvm/unittests/Support/VirtualFileSystemTest.cpp b/llvm/unittests/Support/VirtualFileSystemTest.cpp
--- a/llvm/unittests/Support/VirtualFileSystemTest.cpp
+++ b/llvm/unittests/Support/VirtualFileSystemTest.cpp
@@ -2408,8 +2408,6 @@
 TEST_F(VFSFromYAMLTest, RelativePaths) {
   IntrusiveRefCntPtr<DummyFileSystem> Lower(new DummyFileSystem());
   std::error_code EC;
-  SmallString<128> CWD;
-  EC = llvm::sys::fs::current_path(CWD);
   ASSERT_FALSE(EC);
 
   // Filename at root level without a parent directory.
@@ -2421,9 +2419,12 @@
       "] }",
       Lower);
   ASSERT_TRUE(FS.get() != nullptr);
+  llvm::ErrorOr<std::string> CWD = FS->getCurrentWorkingDirectory();
+  ASSERT_TRUE(CWD);
+
   SmallString<128> ExpectedPathNotInDir("file-not-in-directory.h");
   llvm::sys::fs::make_absolute(ExpectedPathNotInDir);
-  checkContents(FS->dir_begin(CWD, EC), {ExpectedPathNotInDir});
+  checkContents(FS->dir_begin(CWD.get(), EC), {ExpectedPathNotInDir});
 
   // Relative file path.
   FS = getFromYAMLString("{ 'roots': [\n"
@@ -2439,7 +2440,7 @@
   ASSERT_FALSE(EC);
   // Convert to POSIX path for comparison of windows paths
   ASSERT_EQ("relative/path.h",
-            getPosixPath(std::string(I->path().substr(CWD.size() + 1))));
+            getPosixPath(std::string(I->path().substr(CWD->size() + 1))));
 
   // Relative directory path.
   FS = getFromYAMLString(