diff --git a/README.md b/README.md
index 830d27a..3838742 100644
--- a/README.md
+++ b/README.md
@@ -316,7 +316,7 @@ The operator takes a piece of text in string as input.
 It loads tokenizer and pre-trained model using model name.
 and then return text embedding in ndarray.
 
-***__call__(txt)***
+***\_\_call\_\_(txt)***
 
 **Parameters:**