diff --git a/clang/lib/Tooling/CMakeLists.txt b/clang/lib/Tooling/CMakeLists.txt
index efee9227a2c1c7..c7fe324a39dfae 100644
--- a/clang/lib/Tooling/CMakeLists.txt
+++ b/clang/lib/Tooling/CMakeLists.txt
@@ -47,7 +47,6 @@ NodeIntrospection::GetLocations(clang::DynTypedNode const &) {
 } // namespace clang
 "
     )
-    set(CLANG_TOOLING_BUILD_AST_INTROSPECTION "OFF" CACHE BOOL "")
 else()
   # The generation of ASTNodeAPI.json takes a long time in a
   # Debug build due to parsing AST.h. Disable the processing