diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
--- a/clang/include/clang/Lex/Preprocessor.h
+++ b/clang/include/clang/Lex/Preprocessor.h
@@ -1166,6 +1166,9 @@
 
   ~Preprocessor();
 
+  Preprocessor(const Preprocessor &) = delete;
+  Preprocessor &operator=(const Preprocessor &) = delete;
+
   /// Initialize the preprocessor using information about the target.
   ///
   /// \param Target is owned by the caller and must remain valid for the