diff --git a/dnsapi.md b/dnsapi.md
index ed4750a..4474d77 100644
--- a/dnsapi.md
+++ b/dnsapi.md
@@ -2195,8 +2195,8 @@ To issue a cert:
 ## 107. Use dyndnsfree.de API
 
 ```sh
-export df_user="XXX"
-export df_password="XXX"
+export DF_user="XXX"
+export DF_password="XXX"
 ```
 
 To issue a cert:
@@ -2204,7 +2204,7 @@ To issue a cert:
 ./acme.sh --issue --dns dns_df -d example.com -d www.example.com
 ```
 
-The `df_user` and `df_password` will be saved in `~/.acme.sh/account.conf` and will be reused when needed.
+The `DF_user` and `DF_password` will be saved in `~/.acme.sh/account.conf` and will be reused when needed.
 
 ## 108. Use Njalla API