diff --git a/libimagstore/src/fsstore.rs b/libimagstore/src/fsstore.rs
index 2bea1a58..c068f7bd 100644
--- a/libimagstore/src/fsstore.rs
+++ b/libimagstore/src/fsstore.rs
@@ -8,6 +8,7 @@ use std::sync::RwLock;
 
 pub use store::Store;
 pub use store::Result;
+pub use store::FileLockEntry;
 pub use entry::Entry;
 pub use error::StoreError;
 
@@ -44,7 +45,7 @@ impl Store for FSStore {
         unimplemented!()
     }
 
-    fn retrieve(&self, path: PathBuf) -> Result<Arc<RwLock<Entry>>> {
+    fn retrieve<'a>(&'a self, path: PathBuf) -> Result<FileLockEntry<'a, Self>> {
         unimplemented!()
     }
 
@@ -52,7 +53,7 @@ impl Store for FSStore {
         unimplemented!()
     }
 
-    fn update(&self, entry: Arc<RwLock<Entry>>) -> Result<()> {
+    fn update<'a>(&'a self, entry: FileLockEntry<'a, Self>) -> Result<()> {
         unimplemented!()
     }
 
diff --git a/libimagstore/src/store.rs b/libimagstore/src/store.rs
index e1428cc4..eaf90d71 100644
--- a/libimagstore/src/store.rs
+++ b/libimagstore/src/store.rs
@@ -11,13 +11,13 @@ pub use error::StoreError;
 
 pub type Result<T> = RResult<T, StoreError>;
 
-pub trait Store {
+pub trait Store : Sized {
 
     fn location(&self) -> &PathBuf;
 
     fn create(&self, entry: Entry) -> Result<()>;
-    fn retrieve(&self, path: PathBuf) -> Result<Arc<RwLock<Entry>>>;
-    fn update(&self, entry: Arc<RwLock<Entry>>) -> Result<()>;
+    fn retrieve<'a>(&'a self, path: PathBuf) -> Result<FileLockEntry<'a, Self>>;
+    fn update<'a>(&'a self, entry: FileLockEntry<'a, Self>) -> Result<()>;
     fn retrieve_copy(&self, id : String) -> Result<Entry>;
     fn delete(&self, path: PathBuf) -> Result<()>;