diff --git a/clang/include/clang/Basic/SourceManager.h b/clang/include/clang/Basic/SourceManager.h
index fb48430e25ce..9dc19458521c 100644
--- a/clang/include/clang/Basic/SourceManager.h
+++ b/clang/include/clang/Basic/SourceManager.h
@@ -1296,6 +1296,9 @@ private:
   getDecomposedSpellingLocSlowCase(const SrcMgr::SLocEntry *E,
                                    unsigned Offset) const;
   void computeMacroArgsCache(SrcMgr::ContentCache *Content, FileID FID);
+
+  friend class ASTReader;
+  friend class ASTWriter;
 };
 
 
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index e4f9fa693c8a..6c0afb59b40c 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -2633,9 +2633,11 @@ ASTReader::ASTReadResult ASTReader::ReadASTCore(StringRef FileName,
   // Preload SLocEntries.
   for (unsigned I = 0, N = M->PreloadSLocEntries.size(); I != N; ++I) {
     int Index = int(M->PreloadSLocEntries[I] - 1) + F.SLocEntryBaseID;
-    ASTReadResult Result = ReadSLocEntryRecord(Index);
-    if (Result != Success)
-      return Failure;
+    // Load it through the SourceManager and don't call ReadSLocEntryRecord()
+    // directly because the entry may have already been loaded in which case
+    // calling ReadSLocEntryRecord() directly would trigger an assertion in
+    // SourceManager.
+    SourceMgr.getLoadedSLocEntryByID(Index);
   }