diff --git a/clang/utils/perf-training/perf-helper.py b/clang/utils/perf-training/perf-helper.py
index 0dc280de7538..30b9caeffd58 100644
--- a/clang/utils/perf-training/perf-helper.py
+++ b/clang/utils/perf-training/perf-helper.py
@@ -75,7 +75,7 @@ def dtrace(args):
       target = "oneshot$target:::entry"
   else:
       target = "pid$target:::entry"
-  predicate = '%s/probemod=="%s"/' % (target, os.path.basename(args[0]))
+  predicate = '%s/probemod=="%s"/' % (target, os.path.basename(cmd[0]))
   log_timestamp = 'printf("dtrace-TS: %d\\n", timestamp)'
   if opts.use_ustack:
       action = 'ustack(1);'