diff --git a/lib/src/collateral/target_info.rs b/lib/src/collateral/target_info.rs
index 449230e..138a3bf 100644
--- a/lib/src/collateral/target_info.rs
+++ b/lib/src/collateral/target_info.rs
@@ -6,7 +6,7 @@ use crate::Error;
 use crate::utils::Map;
 #[cfg(not(feature = "std"))]
 use alloc::string::String;
-use serde::Deserialize;
+use serde::{Deserialize, Deserializer};
 
 /// Stores various product information
 #[derive(Debug, Deserialize)]
@@ -19,14 +19,30 @@ pub struct TargetInfo {
     #[serde(default = "default_variant")]
     pub variant: String,
     /// Die IDs/names
-    #[serde(default)]
-    pub die_id: Map<String, String>,
+    #[serde(default, deserialize_with = "deserialize_die_ids")]
+    pub die_id: Map<u8, String>,
 }
 
 fn default_variant() -> String {
     String::from("all")
 }
 
+fn deserialize_die_ids<'de, D>(deserializer: D) -> Result<Map<u8, String>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let map: Map<String, String> = Deserialize::deserialize(deserializer)?;
+    Ok(map
+        .into_iter()
+        .filter_map(|(key, value)| {
+            key.parse::<u8>()
+                .inspect_err(|_| log::warn!("Invalid die ID value: {key}"))
+                .ok()
+                .map(|k| (k, value))
+        })
+        .collect())
+}
+
 impl<T: CollateralTree> CollateralManager<T> {
     pub(super) fn update_target_info(&mut self) -> Result<(), Error> {
         self.target_info.clear();
diff --git a/lib/src/header.rs b/lib/src/header.rs
index d4f427d..cdf678d 100644
--- a/lib/src/header.rs
+++ b/lib/src/header.rs
@@ -302,7 +302,7 @@ impl Header {
     #[cfg(feature = "collateral_manager")]
     pub fn die<'a, T: CollateralTree>(&self, cm: &'a CollateralManager<T>) -> Option<&'a str> {
         let target_info = cm.target_info.get(&self.product_id())?;
-        let die_id = target_info.die_id.get(&self.die_id()?.to_string())?;
+        let die_id = target_info.die_id.get(&self.die_id()?)?;
         Some(die_id)
     }
 
diff --git a/lib/tests/header.rs b/lib/tests/header.rs
index 715595f..7263ad3 100644
--- a/lib/tests/header.rs
+++ b/lib/tests/header.rs
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: MIT
 
 use intel_crashlog::prelude::*;
+use std::fs;
 use std::path::Path;
 
 const COLLATERAL_TREE_PATH: &str = "tests/collateral";
@@ -56,3 +57,17 @@ fn decode_header_to_node() {
         NodeType::Field { value: 0x7a }
     );
 }
+
+#[test]
+fn decode_die_id_header() {
+    let cm = CollateralManager::file_system_tree(Path::new(COLLATERAL_TREE_PATH)).unwrap();
+
+    let data = fs::read("tests/samples/dummy_mca_rev2.crashlog").unwrap();
+    let header = Header::from_slice(&data).unwrap().unwrap();
+
+    let die_id = header.die_id().unwrap();
+    assert_eq!(die_id, 1);
+
+    let die = header.die(&cm).unwrap();
+    assert_eq!(die, "io1");
+}