diff --git a/README.md b/README.md
index d6f7ce1..e782d28 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,8 @@
 
 This library permits the creation of 2FA authentification tokens per TOTP, the verification of said tokens, with configurable time skew, validity time of each token, algorithm and number of digits! Default features are kept as lightweight as possible to ensure small binaries and short compilation time
 
+Be aware that some authenticator apps will accept the `SHA256` and `SHA512` algorithms but silently fallback to `SHA1` which will make the `check()` function fail due to mismatched algorithms.
+
 ## Features
 ---
 ### qr