diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0ad0557..d1c8cec 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -279,10 +279,17 @@
 # TODO: docs.
 add_subdirectory(test)
 
-if( LLVM_INCLUDE_TESTS )
-  if( NOT CLANG_BUILT_STANDALONE )
-    add_subdirectory(unittests)
-  endif()
+option(CLANG_BUILD_TESTS
+       "Build Clang unit tests. If OFF, just generate build targets." 
+       LLVM_BUILD_TESTS)
+option(CLANG_INCLUDE_TESTS
+       "Generate build targets for the Clang unit tests."
+       LLVM_INCLUDE_TESTS)
+
+if( CLANG_INCLUDE_TESTS )
+  add_subdirectory(unittests)
+elseif( CLANG_BUILD_TESTS )
+  message(FATAL_ERROR "CLANG_BUILD_TESTS requires CLANG_INCLUDE_TESTS")
 endif()
 
 # Workaround for MSVS10 to avoid the Dialog Hell