diff --git a/nativelink-store/src/filesystem_store.rs b/nativelink-store/src/filesystem_store.rs
index ce542b350..0c83a9f4f 100644
--- a/nativelink-store/src/filesystem_store.rs
+++ b/nativelink-store/src/filesystem_store.rs
@@ -769,14 +769,11 @@ impl<Fe: FileEntry> StoreDriver for FilesystemStore<Fe> {
         keys: &[StoreKey<'_>],
         results: &mut [Option<u64>],
     ) -> Result<(), Error> {
-        // TODO(allada) This is a bit of a hack to get around the lifetime issues with the
-        // existence_cache. We need to convert the digests to owned values to be able to
-        // insert them into the cache. In theory it should be able to elide this conversion
-        // but it seems to be a bit tricky to get right.
-        let keys: Vec<StoreKey<'static>> = keys.iter().map(|v| v.borrow().into_owned()).collect();
         self.evicting_map
-            .sizes_for_keys::<&Vec<StoreKey<'_>>, StoreKey<'static>, &StoreKey<'_>>(
-                &keys, results, false, /* peek */
+            .sizes_for_keys::<_, StoreKeyBorrow<'_>, &StoreKey<'_>>(
+                keys.iter(),
+                results,
+                false, /* peek */
             )
             .await;
         // We need to do a special pass to ensure our zero files exist.
@@ -884,8 +881,8 @@ impl<Fe: FileEntry> StoreDriver for FilesystemStore<Fe> {
             return Ok(());
         }
 
-        let key_borrow: StoreKeyBorrow<'_> = key.borrow().into();
-        let entry = self.evicting_map.get(&key_borrow).await.ok_or_else(|| {
+        let key_borrow: &StoreKeyBorrow<'_> = std::borrow::Borrow::borrow(&key);
+        let entry = self.evicting_map.get(key_borrow).await.ok_or_else(|| {
             make_err!(
                 Code::NotFound,
                 "{} not found in filesystem store here",
diff --git a/nativelink-store/src/memory_store.rs b/nativelink-store/src/memory_store.rs
index 201fce8da..b8993be97 100644
--- a/nativelink-store/src/memory_store.rs
+++ b/nativelink-store/src/memory_store.rs
@@ -26,7 +26,7 @@ use nativelink_metric::MetricsComponent;
 use nativelink_util::buf_channel::{DropCloserReadHalf, DropCloserWriteHalf};
 use nativelink_util::evicting_map::{EvictingMap, LenEntry};
 use nativelink_util::health_utils::{default_health_status_indicator, HealthStatusIndicator};
-use nativelink_util::store_trait::{StoreDriver, StoreKey, UploadSizeInfo};
+use nativelink_util::store_trait::{StoreDriver, StoreKey, StoreKeyBorrow, UploadSizeInfo};
 
 use crate::cas_utils::is_zero_digest;
 
@@ -84,13 +84,11 @@ impl StoreDriver for MemoryStore {
         keys: &[StoreKey<'_>],
         results: &mut [Option<u64>],
     ) -> Result<(), Error> {
-        // TODO(allada): This is a dirty hack to get around the lifetime issues with the
-        // evicting map.
-        let digests: Vec<StoreKey<'static>> =
-            keys.iter().map(|key| key.borrow().into_owned()).collect();
         self.evicting_map
-            .sizes_for_keys::<Vec<StoreKey<'_>>, StoreKey<'static>, StoreKey<'_>>(
-                digests, results, false, /* peek */
+            .sizes_for_keys::<_, StoreKeyBorrow<'_>, &StoreKey<'_>>(
+                keys.iter(),
+                results,
+                false, /* peek */
             )
             .await;
         // We need to do a special pass to ensure our zero digest exist.
diff --git a/nativelink-util/src/store_trait.rs b/nativelink-util/src/store_trait.rs
index 54003d993..02869b583 100644
--- a/nativelink-util/src/store_trait.rs
+++ b/nativelink-util/src/store_trait.rs
@@ -187,6 +187,19 @@ where
     }
 }
 
+impl<'a, 'b> Borrow<StoreKeyBorrow<'a>> for &StoreKey<'b>
+where
+    'b: 'a,
+{
+    fn borrow(&self) -> &StoreKeyBorrow<'a> {
+        // similar to the auto impl impl<T> Borrow<T> for &T
+        // but instead impl impl<U> Borrow<T> for &T
+        // for our new type key wrapper U
+        let y = *self;
+        std::borrow::Borrow::borrow(y)
+    }
+}
+
 /// Holds something that can be converted into a key the
 /// store API can understand. Generally this is a digest
 /// but it can also be a string if the caller wishes to