diff --git a/kallithea/lib/helpers.py b/kallithea/lib/helpers.py
--- a/kallithea/lib/helpers.py
+++ b/kallithea/lib/helpers.py
@@ -862,7 +862,7 @@ def gravatar(email_address, cls='', size
 
     return literal(html)
 
-def gravatar_url(email_address, size=30):
+def gravatar_url(email_address, size=30, default=''):
     # doh, we need to re-import those to mock it later
     from pylons import url
     from pylons import tmpl_context as c
@@ -873,7 +873,7 @@ def gravatar_url(email_address, size=30)
     email_address = email_address or _def
 
     if email_address == _def:
-        return ""
+        return default
 
     parsed_url = urlparse.urlparse(url.current(qualified=True))
     url = (c.visual.gravatar_url or User.DEFAULT_GRAVATAR_URL ) \
diff --git a/kallithea/model/repo.py b/kallithea/model/repo.py
--- a/kallithea/model/repo.py
+++ b/kallithea/model/repo.py
@@ -142,7 +142,7 @@ class RepoModel(BaseModel):
                 'fname': h.escape(u.name),
                 'lname': h.escape(u.lastname),
                 'nname': u.username,
-                'gravatar_lnk': h.gravatar_url(u.email, size=28),
+                'gravatar_lnk': h.gravatar_url(u.email, size=28, default='default'),
                 'gravatar_size': 14,
             } for u in users]
         )
diff --git a/kallithea/public/js/base.js b/kallithea/public/js/base.js
--- a/kallithea/public/js/base.js
+++ b/kallithea/public/js/base.js
@@ -1076,8 +1076,9 @@ var autocompleteHighlightMatch = functio
         + "</span>" + full.substring(matchindex + snippet.length);
 };
 
+// Return html snippet for showing the provided gravatar url
 var gravatar = function(gravatar_lnk, size, cssclass) {
-    if (!gravatar_lnk) {
+    if (!gravatar_lnk || gravatar_lnk == 'default') {
         return '<i class="icon-user {1}" style="font-size: {0}px;"></i>'.format(size, cssclass);
     }
     return '<img alt="" class="{2}" style="width: {0}px; height: {0}px" src="{1}"/>'.format(size, gravatar_lnk, cssclass);
diff --git a/kallithea/templates/pullrequests/pullrequest_show.html b/kallithea/templates/pullrequests/pullrequest_show.html
--- a/kallithea/templates/pullrequests/pullrequest_show.html
+++ b/kallithea/templates/pullrequests/pullrequest_show.html
@@ -279,7 +279,7 @@ ${self.repo_context_bar('showpullrequest
                   fname="${u.name}"
                   lname="${u.lastname}"
                   nname="${u.username}"
-                  gravatar_lnk="${h.gravatar_url(u.email, size=28)}"
+                  gravatar_lnk="${h.gravatar_url(u.email, size=28, default='default')}"
                   gravatar_size="14"
                   title="Click to add reviewer to the list, then Save Changes.">${u.full_name}</a>
               </li>