diff --git a/src/main.rs b/src/main.rs
index cf37707..7718175 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -285,37 +285,6 @@ fn load_ip(path: &Path) -> Result<Option<SavedIPs>> {
         .map(Some)
 }
 
-#[derive(Clone, Copy, Debug)]
-struct Ipv6Prefix {
-    prefix: Ipv6Addr,
-    length: u32,
-}
-
-impl std::fmt::Display for Ipv6Prefix {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let Self { prefix, length } = self;
-        write!(f, "{prefix}/{length}")
-    }
-}
-
-impl std::str::FromStr for Ipv6Prefix {
-    type Err = miette::Error;
-
-    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
-        let (addr, len) = s.split_once('/').wrap_err("missing `/` in ipv6 prefix")?;
-        Ok(Self {
-            prefix: addr
-                .parse()
-                .into_diagnostic()
-                .wrap_err("invalid ipv6 address for ipv6 prefix")?,
-            length: len
-                .parse()
-                .into_diagnostic()
-                .wrap_err("invalid length for ipv6 prefix")?,
-        })
-    }
-}
-
 #[tracing::instrument(err)]
 fn main() -> Result<()> {
     // set panic hook to pretty print with miette's formatter
@@ -468,7 +437,7 @@ where
 struct FritzBoxUpdateParams {
     /// The domain that should be updated
     #[allow(unused)]
-    #[serde(default, deserialize_with = "empty_string_as_none")]
+    #[serde(default)]
     domain: Option<String>,
     /// IPv4 address for the domain
     #[serde(default, deserialize_with = "empty_string_as_none")]
@@ -478,11 +447,11 @@ struct FritzBoxUpdateParams {
     ipv6: Option<Ipv6Addr>,
     /// IPv6 prefix for the home network
     #[allow(unused)]
-    #[serde(default, deserialize_with = "empty_string_as_none")]
-    ipv6prefix: Option<Ipv6Prefix>,
+    #[serde(default)]
+    ipv6prefix: Option<String>,
     /// Whether the networks uses both IPv4 and IPv6
     #[allow(unused)]
-    #[serde(default, deserialize_with = "empty_string_as_none")]
+    #[serde(default)]
     dualstack: Option<String>,
 }