diff --git a/test/lit.cfg b/test/lit.cfg
index 1f08c9320d9..6bc170cdf94 100644
--- a/test/lit.cfg
+++ b/test/lit.cfg
@@ -283,5 +283,10 @@ else:
 if loadable_module:
     config.available_features.add('loadable_module')
 
-if config.enable_assertions:
+# llc knows whether he is compiled with -DNDEBUG.
+import subprocess
+llc_cmd = subprocess.Popen([os.path.join(llvm_tools_dir, 'llc'), '-version'],
+                           stdout = subprocess.PIPE)
+if re.search(r'with assertions', llc_cmd.stdout.read()):
     config.available_features.add('asserts')
+llc_cmd.wait()