diff --git a/Rocket.toml b/Rocket.toml
new file mode 100644
index 0000000..73ef42a
--- /dev/null
+++ b/Rocket.toml
@@ -0,0 +1,3 @@
+[development]
+address = "0.0.0.0"
+port = 3000
diff --git a/src/handlers/list.rs b/src/handlers/list.rs
index 75479cf..1788952 100644
--- a/src/handlers/list.rs
+++ b/src/handlers/list.rs
@@ -112,13 +112,11 @@ mod tests {
         let mut res = client.get("/lists/updatable").header(Accept::JSON).dispatch();
         let body = res.body_string().unwrap();
         let list = serde_json::from_str::<List>(body.as_str()).unwrap();
-        // Switch contentA with contentB and vice versa
-        let new_data = if list.data == "contentA" {
-            "contentB"
-        } else {
-            "contentA"
-        };
-        let new_json = json!({
+        assert_eq!(list.data, "Some content");
+
+        // Try to change the list data, then verify it was changed
+        let new_data = "New content";
+        let mut new_json: serde_json::Value = json!({
             "id": "updatable",
             "index": 1,
             "data": new_data,
@@ -129,8 +127,6 @@ mod tests {
             "name": "Updatable",
             "path": "test/lists/updatablelist"
         });
-
-        // Try to change the list data, then verify it was changed
         let res = client.put("/lists/updatable")
             .header(ContentType::JSON)
             .body(new_json.to_string())
@@ -144,6 +140,14 @@ mod tests {
         let list = serde_json::from_str::<List>(body.as_str()).unwrap();
         assert_eq!(list.data, new_data);
 
+        // ... and change it back
+        *new_json.get_mut("data").unwrap() = json!("Some content");
+        let res = client.put("/lists/updatable")
+            .header(ContentType::JSON)
+            .body(new_json.to_string())
+            .dispatch();
+        assert_eq!(res.status(), Status::Ok);
+
         // Try to change a list that doesn't exist
         let res = client.put("/lists/doesntexit")
             .header(ContentType::JSON)
diff --git a/src/models/list.rs b/src/models/list.rs
index 74ae8b6..91fc5b9 100644
--- a/src/models/list.rs
+++ b/src/models/list.rs
@@ -116,20 +116,22 @@ mod tests {
         let list = lists.iter_mut()
             .find(|list| list.id == "updatable")
             .unwrap();
+        assert_eq!(list.data, "Some content");
 
-        let new_data = match list.data.as_ref() {
-            "contentA" => "contentB",
-            _          => "contentA"
-        };
+        // Update the data van verify it has changed
+        let new_data = "New content";
         list.update_data(&String::from(new_data));
         assert_eq!(list.data, new_data);
 
         // Verify that the data is written to the file of the list by
         // loading them again
-        let lists = List::load_all(Some("test"));
-        let list = lists.iter()
+        let mut lists = List::load_all(Some("test"));
+        let list = lists.iter_mut()
             .find(|list| list.id == "updatable")
             .unwrap();
         assert_eq!(list.data, new_data);
+
+        // ... and change it back again
+        list.update_data(&String::from("Some content"));
     }
 }
diff --git a/test/lists/updatable.list b/test/lists/updatable.list
index f53431b..e041e7d 100644
--- a/test/lists/updatable.list
+++ b/test/lists/updatable.list
@@ -1 +1 @@
-contentB
\ No newline at end of file
+Some content
\ No newline at end of file