diff --git a/netkan/netkan/download_counter.py b/netkan/netkan/download_counter.py
index 85dedaf..e6c8542 100644
--- a/netkan/netkan/download_counter.py
+++ b/netkan/netkan/download_counter.py
@@ -288,7 +288,7 @@ def _download_summary_table(counts: Dict[str, int], how_many: int) -> str:
 
     def log_top(self, how_many: int) -> None:
         if self.output_file and self.output_file.exists():
-            with open(self.output_file) as old_file:
+            with open(self.output_file, encoding='UTF-8') as old_file:
                 old_counts = json.load(old_file)
                 deltas = {ident: count - old_counts[ident]
                           for ident, count in self.counts.items()