--- a/downloads/forms.py	Wed Dec 09 21:16:04 2015 -0600
+++ b/downloads/forms.py	Thu Dec 10 20:57:50 2015 -0600
@@ -5,6 +5,9 @@
 
 from django import forms
 
+from core.html import ImageCheckError
+from core.html import image_check
+from core.markup import site_markup
 from downloads.models import PendingDownload
 from downloads.models import AllowedExtension
 
@@ -16,6 +19,20 @@
     description = forms.CharField(required=False,
             widget=forms.Textarea(attrs={'class': 'markItUp smileyTarget'}))
 
+    def clean_description(self):
+        description = self.cleaned_data['description'].strip()
+        self.html = None
+        if not description:
+            raise forms.ValidationError("Please enter a description")
+
+        self.html = site_markup(description)
+        try:
+            image_check(self.html)
+        except ImageCheckError as ex:
+            raise forms.ValidationError(str(ex))
+
+        return description
+
     def clean_file(self):
         file = self.cleaned_data['file']
         ext = os.path.splitext(file.name)[1]