diff --git a/clang-tools-extra/clangd/ClangdUnit.cpp b/clang-tools-extra/clangd/ClangdUnit.cpp
index 71d7bc1a9fcbd..6bc9551abfdbc 100644
--- a/clang-tools-extra/clangd/ClangdUnit.cpp
+++ b/clang-tools-extra/clangd/ClangdUnit.cpp
@@ -295,10 +295,12 @@ ParsedAST::build(std::unique_ptr<CompilerInvocation> CI,
     CTContext->setASTContext(&Clang->getASTContext());
     CTContext->setCurrentFile(MainInput.getFile());
     CTFactories.createChecks(CTContext.getPointer(), CTChecks);
+    Preprocessor *PP = &Clang->getPreprocessor();
     for (const auto &Check : CTChecks) {
       // FIXME: the PP callbacks skip the entire preamble.
       // Checks that want to see #includes in the main file do not see them.
       Check->registerPPCallbacks(*Clang);
+      Check->registerPPCallbacks(Clang->getSourceManager(), PP, PP);
       Check->registerMatchers(&CTFinder);
     }
   }