diff --git a/tools/infer/utility.py b/tools/infer/utility.py
index 1eebc73f31e6b48a473c20d907ca401ad919fe0b..3d9bdee0ee13af2017deab05e6844a0dd2fb34d3 100644
--- a/tools/infer/utility.py
+++ b/tools/infer/utility.py
@@ -542,7 +542,7 @@ def text_visual(texts,
 def base64_to_cv2(b64str):
     import base64
     data = base64.b64decode(b64str.encode('utf8'))
-    data = np.fromstring(data, np.uint8)
+    data = np.frombuffer(data, np.uint8)
     data = cv2.imdecode(data, cv2.IMREAD_COLOR)
     return data