diff --git a/Readme.md b/Readme.md
index 4455ee6a011b010c052577f2a0066d55f5b19d13..c26d9a2aa4ada1cff93be2be273d47618a9bc5c7 100644
--- a/Readme.md
+++ b/Readme.md
@@ -10,7 +10,7 @@ Requirements
 ------------
 
 Only Records with
-* ISBN/ISBN
+* ISBN/ISSN
 * ZDB ID
 
 will be retrieve the boss data.