diff --git a/cc/makevars.go b/cc/makevars.go
index 5a912e1..88d4639 100644
--- a/cc/makevars.go
+++ b/cc/makevars.go
@@ -75,6 +75,7 @@
 	ctx.Strict("LLVM_OBJCOPY", "${config.ClangBin}/llvm-objcopy")
 	ctx.Strict("LLVM_STRIP", "${config.ClangBin}/llvm-strip")
 	ctx.Strict("PATH_TO_CLANG_TIDY", "${config.ClangBin}/clang-tidy")
+	ctx.Strict("CLANG_TIDY_UNKNOWN_CFLAGS", strings.Join(config.ClangTidyUnknownCflags, " "))
 	ctx.StrictSorted("CLANG_CONFIG_UNKNOWN_CFLAGS", strings.Join(config.ClangUnknownCflags, " "))
 
 	ctx.Strict("RS_LLVM_PREBUILTS_VERSION", "${config.RSClangVersion}")