diff --git a/core/storage/btree.rs b/core/storage/btree.rs
index 65e9c8b49..c1619123e 100644
--- a/core/storage/btree.rs
+++ b/core/storage/btree.rs
@@ -2136,8 +2136,8 @@ impl BTreeCursor {
         if let CursorState::None = &self.state {
             self.state = CursorState::Write(WriteState::Start);
         }
+        let usable_space = self.usable_space();
         let ret = loop {
-            let usable_space = self.usable_space();
             let CursorState::Write(write_state) = &mut self.state else {
                 panic!("expected write state");
             };