diff --git a/ReferenceDataApp/models.py b/ReferenceDataApp/models.py
index b8b322a..35d35a9 100644
--- a/ReferenceDataApp/models.py
+++ b/ReferenceDataApp/models.py
@@ -62,7 +62,7 @@ class City(BaseModel):
 
     def get_n_save_timezone(self):
         from ReferenceDataApp.funcs import tzf
-        self.timezone = tzf.timezone_at(lng=self.geo_lon, lat=self.geo_lat)
+        self.timezone = tzf.timezone_at(lng=float(self.geo_lon), lat=float(self.geo_lat))
         self.save(update_fields=['timezone'])
         return self.timezone