diff --git a/h2time.py b/h2time.py
index 1dc8574..df48b85 100644
--- a/h2time.py
+++ b/h2time.py
@@ -123,7 +123,7 @@ def send_request_pair(self, headers1: list, headers2: list, data1: str = '', dat
         return stream1, stream2
 
     def receive_response(self, headers, stream_id):
-        resp_time = time.time_ns()
+        resp_time = time.perf_counter_ns()
         status_headers = list(filter(lambda x: x[0] == b':status', headers))
         status = '-1'
         if len(status_headers) == 1: