diff --git a/generator/clangversionabstraction.cpp b/generator/clangversionabstraction.cpp
index e106539..0bee2fa 100644
--- a/generator/clangversionabstraction.cpp
+++ b/generator/clangversionabstraction.cpp
@@ -2,17 +2,6 @@
 
 #include "./clangversionabstraction.h"
 
-#include <clang/Lex/Preprocessor.h>
-
 namespace ReflectiveRapidJSON {
 
-clang::FileID createFileIDForMemBuffer(clang::Preprocessor &pp, llvm::MemoryBuffer *buffer, clang::SourceLocation location)
-{
-#if CLANG_VERSION_MAJOR != 3 || CLANG_VERSION_MINOR > 4
-    return pp.getSourceManager().createFileID(maybe_unique(buffer), clang::SrcMgr::C_User, 0, 0, location);
-#else
-    return pp.getSourceManager().createFileIDForMemBuffer(buffer, clang::SrcMgr::C_User, 0, 0, location);
-#endif
-}
-
 } // namespace ReflectiveRapidJSON
diff --git a/generator/clangversionabstraction.h b/generator/clangversionabstraction.h
index a2d8dd4..e4b98ce 100644
--- a/generator/clangversionabstraction.h
+++ b/generator/clangversionabstraction.h
@@ -8,14 +8,8 @@
 
 #include <memory>
 
-namespace clang {
-class Preprocessor;
-}
-
 namespace ReflectiveRapidJSON {
 
-clang::FileID createFileIDForMemBuffer(clang::Preprocessor &pp, llvm::MemoryBuffer *buffer, clang::SourceLocation location);
-
 /*!
  * \brief The MaybeUnique class represents either a std::unique_ptr or a raw pointer.
  * \remarks This is used to support Clang < 3.6 which has not been using unique_ptr in many places yet.