diff --git a/central_backend/src/energy/consumption_history_file.rs b/central_backend/src/energy/consumption_history_file.rs
index 5b9a43d..0ffa290 100644
--- a/central_backend/src/energy/consumption_history_file.rs
+++ b/central_backend/src/energy/consumption_history_file.rs
@@ -45,7 +45,7 @@ impl ConsumptionHistoryFile {
     fn new_memory(day: u64) -> Self {
         Self {
             day,
-            buff: vec![0; 3600 * 24 / TIME_INTERVAL],
+            buff: vec![0; (3600 * 24 / TIME_INTERVAL) + 1],
         }
     }