diff --git a/Makefile b/Makefile
index 288f3d4..6eec517 100644
--- a/Makefile
+++ b/Makefile
@@ -27,7 +27,7 @@
   DIRS := $(filter-out tools docs, $(DIRS))
   OPTIONAL_DIRS :=
 endif
-ifeq ($(MAKECMDGOALS),clang-only)
+ifeq ($(BUILD_CLANG_ONLY),YES)
   DIRS := $(filter-out tools docs unittests, $(DIRS))
 	tools/driver tools/libclang
   OPTIONAL_DIRS :=