diff --git a/hc/front/forms.py b/hc/front/forms.py
index 1e2d58ed..1617a5ef 100644
--- a/hc/front/forms.py
+++ b/hc/front/forms.py
@@ -1,3 +1,5 @@
+from datetime import timedelta as td
+
 from django import forms
 from django.core.validators import RegexValidator
 from hc.front.validators import (CronExpressionValidator, TimezoneValidator,
@@ -23,6 +25,12 @@ class TimeoutForm(forms.Form):
     timeout = forms.IntegerField(min_value=60, max_value=2592000)
     grace = forms.IntegerField(min_value=60, max_value=2592000)
 
+    def clean_timeout(self):
+        return td(seconds=self.cleaned_data["timeout"])
+
+    def clean_grace(self):
+        return td(seconds=self.cleaned_data["grace"])
+
 
 class CronForm(forms.Form):
     schedule = forms.CharField(max_length=100,
diff --git a/hc/front/views.py b/hc/front/views.py
index 0173e0c5..151cbff8 100644
--- a/hc/front/views.py
+++ b/hc/front/views.py
@@ -190,8 +190,8 @@ def update_timeout(request, code):
             return HttpResponseBadRequest()
 
         check.kind = "simple"
-        check.timeout = td(seconds=form.cleaned_data["timeout"])
-        check.grace = td(seconds=form.cleaned_data["grace"])
+        check.timeout = form.cleaned_data["timeout"]
+        check.grace = form.cleaned_data["grace"]
     elif kind == "cron":
         form = CronForm(request.POST)
         if not form.is_valid():