diff --git a/rust/prop_grid_rs/src/commercial.rs b/rust/prop_grid_rs/src/commercial.rs
index 4efbebee..33e07ec8 100644
--- a/rust/prop_grid_rs/src/commercial.rs
+++ b/rust/prop_grid_rs/src/commercial.rs
@@ -13,6 +13,7 @@
 //! and let the scorer fold it in.
 
 use sqlx::PgPool;
+use uuid::Uuid;
 
 const DEFAULT_RADIUS_KM: f64 = 75.0;
 const DEFAULT_BASELINE_DAYS: i64 = 7;
@@ -21,7 +22,7 @@ const MIN_BASELINE_SAMPLES: i64 = 5;
 
 #[derive(Debug, Clone)]
 pub struct LinkLookupEntry {
-    pub link_id: i64,
+    pub link_id: Uuid,
     pub endpoint: (f64, f64),
     pub baseline_dbm: f64,
     pub current_dbm: f64,
@@ -60,7 +61,7 @@ pub async fn build_link_lookup(
     // keys. Failures of that assumption are dropped rather than
     // surfaced — a malformed endpoint is a data-quality issue, not a
     // chain-blocker.
-    let link_rows = sqlx::query_as::<_, (i64, serde_json::Value)>(
+    let link_rows = sqlx::query_as::<_, (Uuid, serde_json::Value)>(
         r#"
         SELECT id, endpoint_a
         FROM commercial_links
@@ -98,7 +99,7 @@ fn extract_endpoint(v: &serde_json::Value) -> Option<(f64, f64)> {
 
 async fn fetch_per_link_degradation(
     pool: &PgPool,
-    link_id: i64,
+    link_id: Uuid,
     baseline_cutoff: chrono::DateTime<chrono::Utc>,
     current_cutoff: chrono::DateTime<chrono::Utc>,
     valid_time: chrono::DateTime<chrono::Utc>,
@@ -204,9 +205,13 @@ fn round2(v: f64) -> f64 {
 mod tests {
     use super::*;
 
-    fn entry(link_id: i64, lat: f64, lon: f64, baseline: f64, current: f64) -> LinkLookupEntry {
+    fn entry(n: u8, lat: f64, lon: f64, baseline: f64, current: f64) -> LinkLookupEntry {
+        // Tests don't care about the actual UUID value, only that each entry
+        // has a distinct identity — a fixed-byte-0 pattern is plenty.
+        let mut bytes = [0u8; 16];
+        bytes[0] = n;
         LinkLookupEntry {
-            link_id,
+            link_id: Uuid::from_bytes(bytes),
             endpoint: (lat, lon),
             baseline_dbm: baseline,
             current_dbm: current,