diff --git a/tools/infer/utility.py b/tools/infer/utility.py
index d27aec63edd2fb5c0240ff0254ce1057b62162b0..bc095baa29e18ff6e97522bd2bfd1639fe7e79dd 100644
--- a/tools/infer/utility.py
+++ b/tools/infer/utility.py
@@ -587,7 +587,7 @@ 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