diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index 096a610..1f28b3b 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -480,7 +480,7 @@
 }
 
 Module *Preprocessor::getCurrentModule() {
-  if (!getLangOpts().CompilingModule)
+  if (!getLangOpts().isCompilingModule())
     return nullptr;
 
   return getHeaderSearchInfo().lookupModule(getLangOpts().CurrentModule);
@@ -795,6 +795,23 @@
 
   // If we have a non-empty module path, load the named module.
   if (!ModuleImportPath.empty()) {
+    // Under the Modules TS, the dot is just part of the module name, and not
+    // a real hierarachy separator. Flatten such module names now.
+    //
+    // FIXME: Is this the right level to be performing this transformation?
+    std::string FlatModuleName;
+    if (getLangOpts().ModulesTS) {
+      for (auto &Piece : ModuleImportPath) {
+        if (!FlatModuleName.empty())
+          FlatModuleName += ".";
+        FlatModuleName += Piece.first->getName();
+      }
+      SourceLocation FirstPathLoc = ModuleImportPath[0].second;
+      ModuleImportPath.clear();
+      ModuleImportPath.push_back(
+          std::make_pair(getIdentifierInfo(FlatModuleName), FirstPathLoc));
+    }
+
     Module *Imported = nullptr;
     if (getLangOpts().Modules) {
       Imported = TheModuleLoader.loadModule(ModuleImportLoc,