diff --git a/lib/commands/stat.js b/lib/commands/stat.js
index 772499c4..4f717f8b 100644
--- a/lib/commands/stat.js
+++ b/lib/commands/stat.js
@@ -169,7 +169,7 @@ function showCal(problems) {
     const idx = now.diff(d, 'days');
 
     const j = (N_WEEKS - idx / N_WEEKDAYS + 1) * 2;
-    if (j >= 0) buf.write(MONTHS[d.month()], j);
+    if (j >= 0) buf.write(MONTHS[d.month()], j | 0);
   }
   log.printf('%7s%s', ' ', buf.toString());