diff --git a/clang/lib/Driver/Driver.cpp b/clang/lib/Driver/Driver.cpp
index 775f3f029861c..d86f47bada86b 100644
--- a/clang/lib/Driver/Driver.cpp
+++ b/clang/lib/Driver/Driver.cpp
@@ -192,7 +192,12 @@ std::string Driver::GetResourcesPath(StringRef BinaryPath) {
 
   StringRef ConfiguredResourceDir(CLANG_RESOURCE_DIR);
   if (!ConfiguredResourceDir.empty()) {
-    llvm::sys::path::append(P, ConfiguredResourceDir);
+    // FIXME: We should fix the behavior of llvm::sys::path::append so we don't
+    // need to check for absolute paths here.
+    if (llvm::sys::path::is_absolute(ConfiguredResourceDir))
+      P = ConfiguredResourceDir;
+    else
+      llvm::sys::path::append(P, ConfiguredResourceDir);
   } else {
     // On Windows, libclang.dll is in bin/.
     // On non-Windows, libclang.so/.dylib is in lib/.
diff --git a/llvm/include/llvm/Support/Path.h b/llvm/include/llvm/Support/Path.h
index 0d8881359b806..0cb517146c04b 100644
--- a/llvm/include/llvm/Support/Path.h
+++ b/llvm/include/llvm/Support/Path.h
@@ -223,6 +223,8 @@ LLVM_ABI bool remove_dots(SmallVectorImpl<char> &path,
 ///   /foo  + bar/f => /foo/bar/f
 ///   /foo/ + bar/f => /foo/bar/f
 ///   foo   + bar/f => foo/bar/f
+///   foo   + /bar/f => foo/bar/f (FIXME: will be changed to /bar/f to align
+///                                with C++17 std::filesystem::path::append)
 /// @endcode
 ///
 /// @param path Set to \a path + \a component.