diff --git a/README.md b/README.md
index 3046f9f..55a1f06 100644
--- a/README.md
+++ b/README.md
@@ -22,11 +22,11 @@ The configuration can contain a list of update targets:
 
 ddnssclient can also be configured using some properties or environment variables
 
-| Property                    | Environment variable         | Value                             | Default |
-|-----------------------------|------------------------------|-----------------------------------|---------|
-| ddnsclient.interval         | DDNSCLIENT_INTERVAL          | e.g. "3600s", "60m", "1h"         | "5m"    |
-| ddnsclient.ip-provider      | DDNSCLIENT_IP_PROVIDER       | an ip lookup provider (see below) | null    |
-| ddnsclient.backoff-duration | DDNS_CLIENT_BACKOFF_DURATION | e.g. "60s", "1m"                  | "60s"   |
+| Property                    | Environment variable        | Value                             | Default |
+|-----------------------------|-----------------------------|-----------------------------------|---------|
+| ddnsclient.interval         | DDNSCLIENT_INTERVAL         | e.g. "3600s", "60m", "1h"         | "5m"    |
+| ddnsclient.ip-provider      | DDNSCLIENT_IP_PROVIDER      | an ip lookup provider (see below) | null    |
+| ddnsclient.backoff-duration | DDNSCLIENT_BACKOFF_DURATION | e.g. "60s", "1m"                  | "60s"   |
 
 ## IP lookup