diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h
index 739f7399895e1..2d114fc8d4e41 100644
--- a/clang/include/clang/Serialization/ASTReader.h
+++ b/clang/include/clang/Serialization/ASTReader.h
@@ -939,7 +939,7 @@ class ASTReader
   /// Sema tracks these to emit deferred diags.
   llvm::SmallSetVector<serialization::DeclID, 4> DeclsToCheckForDeferredDiags;
 
-public:
+private:
   struct ImportedSubmodule {
     serialization::SubmoduleID ID;
     SourceLocation ImportLoc;
@@ -948,7 +948,6 @@ class ASTReader
         : ID(ID), ImportLoc(ImportLoc) {}
   };
 
-private:
   /// A list of modules that were imported by precompiled headers or
   /// any other non-module AST file and have not yet been made visible. If a
   /// module is made visible in the ASTReader, it will be transfered to
@@ -1633,13 +1632,9 @@ class ASTReader
   /// \param ClientLoadCapabilities The set of client load-failure
   /// capabilities, represented as a bitset of the enumerators of
   /// LoadFailureCapabilities.
-  ///
-  /// \param Imported optional out-parameter to append the list of modules
-  /// that were imported by precompiled headers or any other non-module AST file
   ASTReadResult ReadAST(StringRef FileName, ModuleKind Type,
                         SourceLocation ImportLoc,
-                        unsigned ClientLoadCapabilities,
-                        SmallVectorImpl<ImportedSubmodule> *Imported = nullptr);
+                        unsigned ClientLoadCapabilities);
 
   /// Make the entities in the given module and any of its (non-explicit)
   /// submodules visible to name lookup.
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 22bc40a9ce7ba..faeea6685ab95 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -4314,8 +4314,7 @@ static bool SkipCursorToBlock(BitstreamCursor &Cursor, unsigned BlockID) {
 ASTReader::ASTReadResult ASTReader::ReadAST(StringRef FileName,
                                             ModuleKind Type,
                                             SourceLocation ImportLoc,
-                                            unsigned ClientLoadCapabilities,
-                                            SmallVectorImpl<ImportedSubmodule> *Imported) {
+                                            unsigned ClientLoadCapabilities) {
   llvm::TimeTraceScope scope("ReadAST", FileName);
 
   llvm::SaveAndRestore SetCurImportLocRAII(CurrentImportLoc, ImportLoc);
@@ -4506,10 +4505,6 @@ ASTReader::ASTReadResult ASTReader::ReadAST(StringRef FileName,
   }
   UnresolvedModuleRefs.clear();
 
-  if (Imported)
-    Imported->append(PendingImportedModules.begin(),
-                     PendingImportedModules.end());
-
   // FIXME: How do we load the 'use'd modules? They may not be submodules.
   // Might be unnecessary as use declarations are only used to build the
   // module itself.