diff --git a/lostplaces/lostplaces_app/admin.py b/lostplaces/lostplaces_app/admin.py
index d2945df..dc52e86 100644
--- a/lostplaces/lostplaces_app/admin.py
+++ b/lostplaces/lostplaces_app/admin.py
@@ -13,8 +13,8 @@ from lostplaces_app.forms import ExplorerCreationForm, ExplorerChangeForm
 # Register your models here.
 
 class VoucherAdmin(admin.ModelAdmin):
-    fields = ['code', 'expires', 'created']
-    readonly_fields = ['created']
+    fields = ['code', 'expires_when', 'created_when']
+    readonly_fields = ['created_when']
 
 admin.site.register(Explorer)
 admin.site.register(Voucher, VoucherAdmin)
diff --git a/lostplaces/lostplaces_app/models.py b/lostplaces/lostplaces_app/models.py
index 8e1885a..4df6736 100644
--- a/lostplaces/lostplaces_app/models.py
+++ b/lostplaces/lostplaces_app/models.py
@@ -54,11 +54,11 @@ class Voucher(models.Model):
     """
 
     code = models.CharField(unique=True, max_length=30)
-    created = models.DateTimeField(auto_now_add=True)
-    expires = models.DateField()
+    created_when = models.DateTimeField(auto_now_add=True)
+    expires_when = models.DateTimeField()
 
     def __str__(self):
-        return "Voucher " + str(self.pk)
+        return "Voucher " + str(self.code)
 
 
 class Place (models.Model):
diff --git a/lostplaces/lostplaces_app/tests/models/test_voucher_model.py b/lostplaces/lostplaces_app/tests/models/test_voucher_model.py
index c2cb5be..5ab7b4b 100644
--- a/lostplaces/lostplaces_app/tests/models/test_voucher_model.py
+++ b/lostplaces/lostplaces_app/tests/models/test_voucher_model.py
@@ -10,7 +10,7 @@ from lostplaces_app.tests.models import ModelTestCase
 def mock_voucher():
     return Voucher.objects.create(
         code='ayDraJCCwfhcFiYmSR5GrcjcchDfcahv',
-        expires=datetime.datetime.now() + datetime.timedelta(days=1)
+        expires_when=datetime.datetime.now() + datetime.timedelta(days=1)
     )