diff --git a/README.md b/README.md
index 69348bf9..cd277984 100644
--- a/README.md
+++ b/README.md
@@ -260,6 +260,7 @@ You don't have to do anything manually!
 1. LuaDNS.com API
 1. DNSMadeEasy.com API
 1. nsupdate API
+1. ISPConfig 3.1 API
 
 **More APIs coming soon...**
 
diff --git a/dnsapi/README.md b/dnsapi/README.md
index 9a8730c9..6d830b15 100644
--- a/dnsapi/README.md
+++ b/dnsapi/README.md
@@ -201,7 +201,29 @@ acme.sh --issue --dns dns_aws -d example.com -d www.example.com
 
 The `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY` will be saved in `~/.acme.sh/account.conf` and will be reused when needed.
 
-# 11. Use custom API
+## 11. Use ISPConfig 3.1 API
+
+This only works for ISPConfig 3.1 (and newer).
+
+Create a Remote User in the ISPConfig Control Panel. The Remote User must have access to at least `DNS zone functions` and `DNS txt functions`.
+
+```
+export ISPC_User="xxx"
+export ISPC_Password="xxx"
+export ISPC_Api="https://ispc.domain.tld:8080/remote/json.php"
+export ISPC_Api_Insecure=1
+```
+If you have installed ISPConfig on a different port, then alter the 8080 accordingly.
+Leaver ISPC_Api_Insecure set to 1 if you have not a valid ssl cert for your installation. Change it to 0 if you have a valid ssl cert.
+
+To issue a cert:
+```
+acme.sh --issue --dns dns_ispconfig -d example.com -d www.example.com
+```
+
+The `ISPC_User`, `ISPC_Password`, `ISPC_Api`and `ISPC_Api_Insecure` will be saved in `~/.acme.sh/account.conf` and will be reused when needed.
+
+# 12. Use custom API
 
 If your API is not supported yet, you can write your own DNS API.
 
@@ -218,6 +240,6 @@ acme.sh --issue --dns dns_myapi -d example.com -d www.example.com
 For more details, please check our sample script: [dns_myapi.sh](dns_myapi.sh)
 
 
-## 12. Use lexicon DNS API
+## 13. Use lexicon DNS API
 
 https://github.com/Neilpang/acme.sh/wiki/How-to-use-lexicon-dns-api