diff --git a/src/morethantext/mod.rs b/src/morethantext/mod.rs
index afef5c0..acf0d8f 100644
--- a/src/morethantext/mod.rs
+++ b/src/morethantext/mod.rs
@@ -196,6 +196,7 @@ mod datatypes {
 
 #[derive(Debug)]
 enum FromCache {
+    Ok,
     Data(HashMap<String, DataType>),
     Error(MTTError),
 }
@@ -205,8 +206,29 @@ struct CacheQuery {
     reply: Sender<FromCache>,
 }
 
+struct CacheCommit {
+    reply: Sender<FromCache>,
+}
+
+impl CacheCommit {
+    fn new(channel: Sender<FromCache>) -> Self {
+        Self { reply: channel }
+    }
+}
+
+mod commits {
+    use super::*;
+
+    #[test]
+    fn create() {
+        let (s, _) = unbounded();
+        CacheCommit::new(s);
+    }
+}
+
 enum ToCache {
     Query(CacheQuery),
+    Commit(CacheCommit),
 }
 
 #[derive(Clone)]
@@ -265,6 +287,7 @@ impl Cache {
                         }
                     }
                 }
+                ToCache::Commit(data) => data.reply.send(FromCache::Ok).await.unwrap(),
             }
         }
     }
@@ -294,10 +317,7 @@ mod caches {
             ids.push(id.to_string());
         }
         let (s, r) = unbounded();
-        let msg = ToCache::Query( CacheQuery {
-            ids: ids,
-            reply: s,
-        });
+        let msg = ToCache::Query(CacheQuery { ids: ids, reply: s });
         channel.send(msg).await.unwrap();
         r.recv().await.unwrap()
     }
@@ -329,6 +349,20 @@ mod caches {
             _ => assert!(false, "{:?} should have been an error.", result),
         }
     }
+
+    #[async_std::test]
+    async fn empty_commit() {
+        let dir = tempdir().unwrap();
+        let s_cache = start_cache(dir.path()).await;
+        let (s, r) = unbounded();
+        let msg = ToCache::Commit(CacheCommit::new(s));
+        s_cache.send(msg).await.unwrap();
+        let result = r.recv().await.unwrap();
+        match result {
+            FromCache::Ok => (),
+            _ => assert!(false, "{:?} should have been an error.", result),
+        }
+    }
 }
 
 pub async fn start_db<P>(_dir: P) -> Result<MoreThanText, MTTError>