diff --git a/tank/examples/opt/opt_perf_comparison.py b/tank/examples/opt/opt_perf_comparison.py
index 46cb7072f0..025a2cf40a 100644
--- a/tank/examples/opt/opt_perf_comparison.py
+++ b/tank/examples/opt/opt_perf_comparison.py
@@ -168,7 +168,7 @@ def save_json(data, filename):
 
 
 def collect_huggingface_logits(
-    model_name: str, max_seq_len: int, save_json: bool
+    model_name: str, max_seq_len: int, to_save_json: bool
 ) -> Tuple[float, float]:
     # Load
     t0 = time.time()
@@ -194,11 +194,11 @@ def collect_huggingface_logits(
     for idx, tokens in enumerate(tokenized_prompts):
         print("prompt: {}".format(PROMPTS[idx]))
         logits = run_huggingface_model(model_wrapper, tokens)
-        if save_json:
+        if to_save_json:
             results.append([PROMPTS[idx], logits[0].tolist()])
     run_time = time.time() - t0
     print("--- Took {} seconds to run Huggingface.".format(run_time))
-    if save_json:
+    if to_save_json:
         save_json(results, "/tmp/huggingface.json")
     run_memory_info = get_memory_info()
     return {
@@ -215,7 +215,10 @@ def collect_huggingface_logits(
 
 
 def collect_shark_logits(
-    model_name: str, max_seq_len: int, recompile_shark: bool, save_json: bool
+    model_name: str,
+    max_seq_len: int,
+    recompile_shark: bool,
+    to_save_json: bool,
 ) -> Tuple[float, float]:
     # Load
     t0 = time.time()
@@ -246,11 +249,11 @@ def collect_shark_logits(
         print("prompt: {}".format(PROMPTS[idx]))
         logits = run_shark_model(model_wrapper, tokens)
         lst = [e.tolist() for e in logits]
-        if save_json:
+        if to_save_json:
             results.append([PROMPTS[idx], lst])
     run_time = time.time() - t0
     print("--- Took {} seconds to run Shark.".format(run_time))
-    if save_json:
+    if to_save_json:
         save_json(results, "/tmp/shark.json")
     platform_postfix = "-compile" if recompile_shark else "-precompiled"
     run_memory_info = get_memory_info()