diff --git a/src/repo/fs.rs b/src/repo/fs.rs
index 3c4bb07..01e0678 100644
--- a/src/repo/fs.rs
+++ b/src/repo/fs.rs
@@ -95,7 +95,7 @@ impl Repository for FsRepo {
             return Err(Error::NotFound);
         }
 
-        let mut task = &mut tasks[id];
+        let mut task = &mut tasks[id - 1];
         if let Some(name) = update_data.name {
             task.name = name;
         }