diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 23060c3..e912727 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -363,10 +363,19 @@ module ApplicationHelper
     'default'
   end
 
+  # generates a image tag for the profile. 
+  #
+  # If the profile has no image set yet, then a default image is used.
   def profile_image(profile)
-    image_tag(profile.image.public_filename(:thumb)) if profile.image
+    if profile.image
+      image_tag(profile.image.public_filename(:thumb))
+    else
+      image_tag('peopleblock.png')
+    end
   end
 
+  # displays a link to the profile homepage with its image (as generated by
+  # #profile_image) and its name below it.
   def profile_image_link(profile)
     link_to(profile_image(profile) + tag('br') + profile.name, profile.url)
   end
--
libgit2 0.21.2