diff --git a/crates/tor-chanmgr/src/mgr/map.rs b/crates/tor-chanmgr/src/mgr/map.rs
index 1ed732047..af850ba71 100644
--- a/crates/tor-chanmgr/src/mgr/map.rs
+++ b/crates/tor-chanmgr/src/mgr/map.rs
@@ -9,10 +9,10 @@ use std::collections::{hash_map, HashMap};
 use std::result::Result as StdResult;
 use std::sync::Arc;
 use tor_error::{internal, into_internal};
-use tor_netdir::NetDir;
+use tor_netdir::{params::CHANNEL_PADDING_TIMEOUT_UPPER_BOUND, NetDir};
 use tor_proto::channel::padding::ParametersBuilder as PaddingParametersBuilder;
 use tor_proto::ChannelsConfig;
-use tor_units::IntegerMilliseconds;
+use tor_units::BoundedInt32;
 use tracing::info;
 
 /// A map from channel id to channel state, plus necessary auxiliary state
@@ -345,16 +345,14 @@ fn update_padding_parameters_from_netdir(
     // TODO and with reduced padding, send CELL_PADDING_NEGOTIATE
     let (low, high) = (&params.nf_ito_low, &params.nf_ito_high);
 
-    let low = IntegerMilliseconds::<u32>::new(
-        low.get()
-            .try_into()
-            .map_err(|_| "low value out of range?!")?,
-    );
-    let high = IntegerMilliseconds::<u32>::new(
-        high.get()
-            .try_into()
-            .map_err(|_| "high value out of range?!")?,
-    );
+    let conv_timing_param =
+        |bounded: BoundedInt32<0, CHANNEL_PADDING_TIMEOUT_UPPER_BOUND>| bounded.get().try_into();
+    let low = low
+        .try_map(conv_timing_param)
+        .map_err(|_| "low value out of range?!")?;
+    let high = high
+        .try_map(conv_timing_param)
+        .map_err(|_| "high value out of range?!")?;
 
     if high > low {
         return Err("high > low");
diff --git a/crates/tor-netdir/src/params.rs b/crates/tor-netdir/src/params.rs
index 82f36253d..54da07099 100644
--- a/crates/tor-netdir/src/params.rs
+++ b/crates/tor-netdir/src/params.rs
@@ -276,16 +276,16 @@ pub struct NetParameters {
         from "min_paths_for_circs_pct",
 
     /// Channel padding, low end of random padding interval, milliseconds
-    pub nf_ito_low: BoundedInt32<0, CHANNEL_PADDING_TIMEOUT_UPPER_BOUND> = (1500)
+    pub nf_ito_low: IntegerMilliseconds<BoundedInt32<0, CHANNEL_PADDING_TIMEOUT_UPPER_BOUND>> = (1500)
         from "nf_ito_low",
     /// Channel padding, high end of random padding interval, milliseconds
-    pub nf_ito_high: BoundedInt32<0, CHANNEL_PADDING_TIMEOUT_UPPER_BOUND> = (9500)
+    pub nf_ito_high: IntegerMilliseconds<BoundedInt32<0, CHANNEL_PADDING_TIMEOUT_UPPER_BOUND>> = (9500)
         from "nf_ito_high",
     /// Channel padding, low end of random padding interval (reduced padding) milliseconds
-    pub nf_ito_low_reduced: BoundedInt32<0, CHANNEL_PADDING_TIMEOUT_UPPER_BOUND> = (9000)
+    pub nf_ito_low_reduced: IntegerMilliseconds<BoundedInt32<0, CHANNEL_PADDING_TIMEOUT_UPPER_BOUND>> = (9000)
         from "nf_ito_low_reduced",
     /// Channel padding, high end of random padding interval (reduced padding) , milliseconds
-    pub nf_ito_high_reduced: BoundedInt32<0, CHANNEL_PADDING_TIMEOUT_UPPER_BOUND> = (14000)
+    pub nf_ito_high_reduced: IntegerMilliseconds<BoundedInt32<0, CHANNEL_PADDING_TIMEOUT_UPPER_BOUND>> = (14000)
         from "nf_ito_high_reduced",
 
     /// The minimum sendme version to accept.
@@ -526,10 +526,10 @@ mod test {
         assert_eq!(p.cbt_min_circs_for_estimate.get(), 5);
         assert_eq!(p.cbt_timeout_quantile.as_percent().get(), 61);
         assert_eq!(p.cbt_abandon_quantile.as_percent().get(), 15);
-        assert_eq!(p.nf_ito_low.get(), 1_000);
-        assert_eq!(p.nf_ito_high.get(), 20_000);
-        assert_eq!(p.nf_ito_low_reduced.get(), 3_000);
-        assert_eq!(p.nf_ito_high_reduced.get(), 40_000);
+        assert_eq!(p.nf_ito_low.as_millis().get(), 1_000);
+        assert_eq!(p.nf_ito_high.as_millis().get(), 20_000);
+        assert_eq!(p.nf_ito_low_reduced.as_millis().get(), 3_000);
+        assert_eq!(p.nf_ito_high_reduced.as_millis().get(), 40_000);
         assert_eq!(
             Duration::try_from(p.unused_client_circ_timeout_while_learning_cbt).unwrap(),
             Duration::from_secs(1900)