diff --git a/crates/skate-game/src/game_audio/library.rs b/crates/skate-game/src/game_audio/library.rs
index 47b79c3f..a9f6164a 100644
--- a/crates/skate-game/src/game_audio/library.rs
+++ b/crates/skate-game/src/game_audio/library.rs
@@ -87,7 +87,9 @@ pub(crate) struct GrainTuningJson {
     #[serde(default)]
     owner: OwnerJson,
     /// Collision material (tag − 1) → rolling surface 1–14 (`Sk8::AudioSurfaceMap`).
+    /// Read only by the vault check (`grain_for_matches_the_vault_surface_map_and_the_bed_loads`).
     #[serde(default)]
+    #[cfg_attr(not(test), allow(dead_code))]
     pub surface_map: Vec<u32>,
 }
 
@@ -1460,6 +1462,7 @@ impl Library {
 
     /// Collision material → rolling surface (`Sk8::AudioSurfaceMap`, 95 entries; empty before
     /// 2026-10-02 installs).
+    #[cfg(test)]
     pub(crate) fn surface_map(&self) -> &[u32] {
         &self.manifest.grain_player.surface_map
     }
diff --git a/crates/skate-game/src/game_audio/native/prefetch.rs b/crates/skate-game/src/game_audio/native/prefetch.rs
index bcb80261..3b8da4b7 100644
--- a/crates/skate-game/src/game_audio/native/prefetch.rs
+++ b/crates/skate-game/src/game_audio/native/prefetch.rs
@@ -100,7 +100,8 @@ impl Prefetch {
         }
     }
 
-    /// Whether the bank was requested and not taken or dropped since.
+    /// Whether the bank was requested and not taken or dropped since (tests).
+    #[cfg(test)]
     pub(crate) fn contains(&self, stem: &str) -> bool {
         self.slots.contains_key(stem)
     }