Index: clang-tidy/tool/CMakeLists.txt
===================================================================
--- clang-tidy/tool/CMakeLists.txt
+++ clang-tidy/tool/CMakeLists.txt
@@ -5,6 +5,9 @@
 add_clang_executable(clang-tidy
   ClangTidyMain.cpp
   )
+add_dependencies(clang-tidy
+  clang-headers
+  )
 target_link_libraries(clang-tidy
   clangAST
   clangASTMatchers