diff --git a/src/tools/mod.rs b/src/tools/mod.rs
index d8ed7275..03b9da86 100644
--- a/src/tools/mod.rs
+++ b/src/tools/mod.rs
@@ -16,7 +16,6 @@ pub mod apt;
 pub mod config;
 pub mod disks;
 
-pub mod serde_filter;
 pub mod statistics;
 pub mod subscription;
 pub mod systemd;
diff --git a/src/tools/serde_filter.rs b/src/tools/serde_filter.rs
deleted file mode 100644
index dc579e4e..00000000
--- a/src/tools/serde_filter.rs
+++ /dev/null
@@ -1,97 +0,0 @@
-use std::marker::PhantomData;
-
-use serde::Deserialize;
-
-/// Helper to filter data while deserializing it.
-///
-/// An example use case is filtering out expired registration challenges at load time of our TFA
-/// config:
-///
-/// ```
-/// # use proxmox_backup::tools::serde_filter::FilteredVecVisitor;
-/// # use serde::{Deserialize, Deserializer, Serialize};
-/// # const CHALLENGE_TIMEOUT: i64 = 2 * 60;
-/// #[derive(Deserialize)]
-/// struct Challenge {
-///     /// Expiration time as unix epoch.
-///     expires: i64,
-///
-///     // ...other entries...
-/// }
-///
-/// #[derive(Default, Deserialize)]
-/// #[serde(deny_unknown_fields)]
-/// #[serde(rename_all = "kebab-case")]
-/// pub struct TfaUserData {
-///     // ...other entries...
-///
-///     #[serde(skip_serializing_if = "Vec::is_empty", default)]
-///     #[serde(deserialize_with = "filter_expired_registrations")]
-///     registrations: Vec<Challenge>,
-/// }
-///
-/// fn filter_expired_registrations<'de, D>(deserializer: D) -> Result<Vec<Challenge>, D::Error>
-/// where
-///     D: Deserializer<'de>,
-/// {
-///     let expire_before = proxmox_time::epoch_i64() - CHALLENGE_TIMEOUT;
-///
-///     Ok(deserializer.deserialize_seq(
-///         FilteredVecVisitor::new(
-///             "a u2f registration challenge entry",
-///             move |c: &Challenge| c.expires < expire_before,
-///         )
-///     )?)
-/// }
-/// ```
-pub struct FilteredVecVisitor<F, T>
-where
-    F: Fn(&T) -> bool
-{
-    filter: F,
-    expecting: &'static str,
-    _ty: PhantomData<T>,
-}
-
-impl<F, T> FilteredVecVisitor<F, T>
-where
-    F: Fn(&T) -> bool,
-{
-    pub fn new(expecting: &'static str, filter: F) -> Self {
-        Self {
-            filter,
-            expecting,
-            _ty: PhantomData,
-        }
-    }
-}
-
-impl<'de, F, T> serde::de::Visitor<'de> for FilteredVecVisitor<F, T>
-where
-    F: Fn(&T) -> bool,
-    T: Deserialize<'de>,
-{
-    type Value = Vec<T>;
-
-    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
-        formatter.write_str(self.expecting)
-    }
-
-    fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
-    where
-        A: serde::de::SeqAccess<'de>,
-    {
-        let mut out = match seq.size_hint() {
-            Some(hint) => Vec::with_capacity(hint),
-            None => Vec::new(),
-        };
-
-        while let Some(entry) = seq.next_element::<T>()? {
-            if (self.filter)(&entry) {
-                out.push(entry);
-            }
-        }
-
-        Ok(out)
-    }
-}