diff --git a/lib/hx509/hx509_err.et b/lib/hx509/hx509_err.et
index c1dfaf587..5e69532ea 100644
--- a/lib/hx509/hx509_err.et
+++ b/lib/hx509/hx509_err.et
@@ -65,6 +65,7 @@ error_code RSA_PUBLIC_ENCRYPT, "RSA public encyption failed"
 error_code RSA_PRIVATE_ENCRYPT, "RSA public encyption failed"
 error_code RSA_PUBLIC_DECRYPT, "RSA private decryption failed"
 error_code RSA_PRIVATE_DECRYPT, "RSA private decryption failed"
+error_code ALGORITHM_BEST_BEFORE, "Algorithm has passed its best before date"
 
 # revoke related errors
 index 96