diff --git a/hwmonDaemon.py b/hwmonDaemon.py
index 3a6ab26..c985e94 100644
--- a/hwmonDaemon.py
+++ b/hwmonDaemon.py
@@ -783,7 +783,10 @@ class SystemHealthMonitor:
 
             # Load historical data with file locking
             history = []
-            file_mode = 'r+' if os.path.exists(historical_file) else 'w+'
+            if os.path.exists(historical_file) and os.path.getsize(historical_file) > 0:
+                file_mode = 'r+'
+            else:
+                file_mode = 'w+'
 
             with open(historical_file, file_mode) as f:
                 # Acquire exclusive lock