diff --git a/cas/store/memory_store.rs b/cas/store/memory_store.rs
index 63c5167a1..410da84cf 100644
--- a/cas/store/memory_store.rs
+++ b/cas/store/memory_store.rs
@@ -15,7 +15,7 @@ use evicting_map::EvictingMap;
 use traits::{ResultFuture, StoreTrait, UploadSizeInfo};
 
 pub struct MemoryStore {
-    map: Mutex<EvictingMap<Instant>>,
+    map: Mutex<EvictingMap<Vec<u8>, Instant>>,
 }
 
 impl MemoryStore {
@@ -38,7 +38,7 @@ impl StoreTrait for MemoryStore {
     fn has<'a>(self: std::pin::Pin<&'a Self>, digest: DigestInfo) -> ResultFuture<'a, Option<usize>> {
         Box::pin(async move {
             let mut map = self.map.lock().await;
-            Ok(map.size_for_key(&digest))
+            Ok(map.size_for_key(&digest).map(|v| v as usize))
         })
     }
 
diff --git a/util/evicting_map.rs b/util/evicting_map.rs
index e9347decc..a1201e65b 100644
--- a/util/evicting_map.rs
+++ b/util/evicting_map.rs
@@ -21,21 +21,31 @@ impl InstantWrapper for Instant {
     }
 }
 
-struct EvictionItem {
+struct EvictionItem<T: LenEntry> {
     seconds_since_anchor: u32,
-    data: Arc<Vec<u8>>,
+    data: Arc<T>,
 }
 
-pub struct EvictingMap<T: InstantWrapper> {
-    lru: LruCache<DigestInfo, EvictionItem>,
-    anchor_time: T,
+pub trait LenEntry {
+    fn len(&self) -> usize;
+}
+
+impl LenEntry for Vec<u8> {
+    fn len(&self) -> usize {
+        <Vec<u8>>::len(self)
+    }
+}
+
+pub struct EvictingMap<T: LenEntry, I: InstantWrapper> {
+    lru: LruCache<DigestInfo, EvictionItem<T>>,
+    anchor_time: I,
     sum_store_size: usize,
     max_bytes: usize,
     max_seconds: u32,
 }
 
-impl<T: InstantWrapper> EvictingMap<T> {
-    pub fn new(config: &EvictionPolicy, anchor_time: T) -> Self {
+impl<T: LenEntry, I: InstantWrapper> EvictingMap<T, I> {
+    pub fn new(config: &EvictionPolicy, anchor_time: I) -> Self {
         let mut lru = LruCache::unbounded();
         if config.max_count != 0 {
             lru = LruCache::new(config.max_count.try_into().expect("Could not convert max_count to u64"));
@@ -81,7 +91,7 @@ impl<T: InstantWrapper> EvictingMap<T> {
         None
     }
 
-    pub fn get<'a>(&'a mut self, hash: &DigestInfo) -> Option<&'a Arc<Vec<u8>>> {
+    pub fn get<'a>(&'a mut self, hash: &DigestInfo) -> Option<&'a Arc<T>> {
         if let Some(mut entry) = self.lru.get_mut(hash) {
             entry.seconds_since_anchor = self.anchor_time.elapsed().as_secs() as u32;
             return Some(&entry.data);
@@ -89,7 +99,7 @@ impl<T: InstantWrapper> EvictingMap<T> {
         None
     }
 
-    pub fn insert(&mut self, hash: DigestInfo, data: Arc<Vec<u8>>) {
+    pub fn insert(&mut self, hash: DigestInfo, data: Arc<T>) {
         let new_item_size = data.len();
         let eviction_item = EvictionItem {
             seconds_since_anchor: self.anchor_time.elapsed().as_secs() as u32,
diff --git a/util/tests/evicting_map_test.rs b/util/tests/evicting_map_test.rs
index 3d79851a6..a136cfd46 100644
--- a/util/tests/evicting_map_test.rs
+++ b/util/tests/evicting_map_test.rs
@@ -31,7 +31,7 @@ mod evicting_map_tests {
 
     #[tokio::test]
     async fn insert_purges_at_max_count() -> Result<(), Error> {
-        let mut evicting_map = EvictingMap::new(
+        let mut evicting_map = EvictingMap::<Vec<u8>, Instant>::new(
             &EvictionPolicy {
                 max_count: 3,
                 max_seconds: 0,
@@ -70,7 +70,7 @@ mod evicting_map_tests {
 
     #[tokio::test]
     async fn insert_purges_at_max_bytes() -> Result<(), Error> {
-        let mut evicting_map = EvictingMap::new(
+        let mut evicting_map = EvictingMap::<Vec<u8>, Instant>::new(
             &EvictionPolicy {
                 max_count: 0,
                 max_seconds: 0,
@@ -110,7 +110,7 @@ mod evicting_map_tests {
 
     #[tokio::test]
     async fn insert_purges_at_max_seconds() -> Result<(), Error> {
-        let mut evicting_map = EvictingMap::new(
+        let mut evicting_map = EvictingMap::<Vec<u8>, MockInstantWrapped>::new(
             &EvictionPolicy {
                 max_count: 0,
                 max_seconds: 5,
@@ -154,7 +154,7 @@ mod evicting_map_tests {
 
     #[tokio::test]
     async fn get_refreshes_time() -> Result<(), Error> {
-        let mut evicting_map = EvictingMap::new(
+        let mut evicting_map = EvictingMap::<Vec<u8>, MockInstantWrapped>::new(
             &EvictionPolicy {
                 max_count: 0,
                 max_seconds: 3,
@@ -193,7 +193,7 @@ mod evicting_map_tests {
 
     #[tokio::test]
     async fn contains_key_refreshes_time() -> Result<(), Error> {
-        let mut evicting_map = EvictingMap::new(
+        let mut evicting_map = EvictingMap::<Vec<u8>, MockInstantWrapped>::new(
             &EvictionPolicy {
                 max_count: 0,
                 max_seconds: 3,
@@ -232,7 +232,7 @@ mod evicting_map_tests {
 
     #[tokio::test]
     async fn hashes_equal_sizes_different_doesnt_override() -> Result<(), Error> {
-        let mut evicting_map = EvictingMap::new(
+        let mut evicting_map = EvictingMap::<Vec<u8>, Instant>::new(
             &EvictionPolicy {
                 max_count: 0,
                 max_seconds: 0,