diff --git a/crates/core/src/backend/lock.rs b/crates/core/src/backend/lock.rs
index 24c29db6..3602eb85 100644
--- a/crates/core/src/backend/lock.rs
+++ b/crates/core/src/backend/lock.rs
@@ -68,6 +68,15 @@ impl ReadBackend for LockBackend {
     }
 }
 
+fn path(tpe: FileType, id: &Id) -> String {
+    let hex_id = id.to_hex();
+    match tpe {
+        FileType::Config => "config".into(),
+        FileType::Pack => format!("data/{}/{}", &hex_id[0..2], &*hex_id),
+        _ => format!("{}/{}", tpe.dirname(), &*hex_id),
+    }
+}
+
 impl WriteBackend for LockBackend {
     fn create(&self) -> Result<()> {
         self.be.create()
@@ -86,14 +95,13 @@ impl WriteBackend for LockBackend {
     }
 
     fn lock(&self, tpe: FileType, id: &Id, until: Option<DateTime<Local>>) -> Result<()> {
+        let until = until.map_or_else(|| String::new(), |u| format!("{}", u.to_rfc3339()));
+        let path = path(tpe, id);
         let args = self.command.args().iter().map(|c| {
-            let mut c = c
-                .replace("%id", &id.to_string())
-                .replace("%type", tpe.dirname());
-            if let Some(until) = until {
-                c = c.replace("%until", &until.to_string());
-            }
-            c
+            c.replace("%id", &id.to_string())
+                .replace("%type", tpe.dirname())
+                .replace("%path", &path)
+                .replace("%until", &until)
         });
         debug!("calling {:?}...", self.command);
         let status = Command::new(self.command.command()).args(args).status()?;