diff --git a/django/contrib/admin/options.py b/django/contrib/admin/options.py
index 86e3e1d..6605d2b 100644
--- a/django/contrib/admin/options.py
+++ b/django/contrib/admin/options.py
@@ -111,9 +111,9 @@ class AdminField(object):
         classes = []
         if self.is_checkbox:
             classes.append(u'vCheckboxLabel')
-            contents = escape(self.field.label)
+            contents = escape(force_unicode(self.field.label))
         else:
-            contents = escape(self.field.label) + u':'
+            contents = escape(force_unicode(self.field.label)) + u':'
         if self.field.field.required:
             classes.append(u'required')
         if not self.is_first: