diff --git a/AKModel/models.py b/AKModel/models.py
index ca7fd3a37f79eb85c5f70ede84f25732f5789906..b371953669e9e5d594132dbe351d44d4c6f28d7d 100644
--- a/AKModel/models.py
+++ b/AKModel/models.py
@@ -348,7 +348,7 @@ class AKSlot(models.Model):
         Display duration of slot in format hours:minutes, e.g. 1.5 -> "1:30"
         """
         hours, minutes = divmod(self.duration * 60, 60)
-        return f"{hours}:{minutes:2.0f}"
+        return f"{int(hours)}:{int(minutes):02}"
 
     @property
     def start_simplified(self):