diff --git a/crates/model/src/mixer.rs b/crates/model/src/mixer.rs
index e9a7867..001f2a1 100644
--- a/crates/model/src/mixer.rs
+++ b/crates/model/src/mixer.rs
@@ -425,7 +425,7 @@ pub enum Route {
 pub struct Insert {
     /// Registry id from `soundcraft-dsp` (e.g. `eq7`, `comp`).
     pub plugin: String,
-    #[serde(default)]
+    #[serde(default, deserialize_with = "finite_params")]
     pub params: BTreeMap<String, f32>,
     #[serde(default)]
     pub bypass: bool,
@@ -577,6 +577,13 @@ pub(crate) fn finite_or(v: f32, d: f32) -> f32 {
     if v.is_finite() { v } else { d }
 }
 
+/// Parameters saved as `null` (how JSON writes NaN and infinity) or beyond `f32` are dropped, so
+/// they keep their defaults instead of failing the whole session.
+fn finite_params<'de, D: serde::Deserializer<'de>>(d: D) -> Result<BTreeMap<String, f32>, D::Error> {
+    let params: BTreeMap<String, Option<f64>> = serde::Deserialize::deserialize(d)?;
+    Ok(params.into_iter().filter_map(|(k, v)| Some((k, v.map(|v| v as f32).filter(|v| v.is_finite())?))).collect())
+}
+
 /// Fader taper used by Pro Tools-style faders: position 0..1 ↔ dB (-inf..+12).
 pub fn fader_pos_to_db(pos: f32) -> f32 {
     let p = finite_or(pos, 0.0).clamp(0.0, 1.0);
@@ -624,6 +631,16 @@ mod tests {
         assert_eq!(bad.state_bytes(), None);
     }
 
+    #[test]
+    fn params_saved_as_null_or_out_of_range_are_dropped() {
+        let mut i = Insert::new("eq_7band");
+        i.params.extend([("gain".to_string(), f32::NAN), ("q".to_string(), 0.7)]);
+        let back: Insert = serde_json::from_str(&serde_json::to_string(&i).unwrap()).unwrap();
+        assert_eq!(back.params, BTreeMap::from([("q".to_string(), 0.7)]));
+        let big: Insert = serde_json::from_str(r#"{"plugin":"x","params":{"gain":1e39,"q":0.5}}"#).unwrap();
+        assert_eq!(big.params, BTreeMap::from([("q".to_string(), 0.5)]));
+    }
+
     #[test]
     fn fader_taper_round_trips() {
         for db in [-100.0f32, -60.0, -24.0, -10.0, 0.0, 6.0, 12.0] {