diff --git a/highfive/newpr.py b/highfive/newpr.py
index 2634303e..802a90ac 100755
--- a/highfive/newpr.py
+++ b/highfive/newpr.py
@@ -12,6 +12,7 @@
 import gzip
 import re
 import os
+from retry import retry
 
 from highfive import irc, payload
 
@@ -47,6 +48,9 @@
 class UnsupportedRepoError(IOError):
     pass
 
+class HttpClientError(Exception):
+    pass
+
 class HighfiveHandler(object):
     def __init__(self, payload):
         self.payload = payload
@@ -102,6 +106,7 @@ def api_req(self, method, url, data=None, media_type=None):
         body = f.read()
         return { "header": header, "body": body }
 
+    @retry(HttpClientError, delay=1, backoff=2, max_delay=3)
     def set_assignee(self, assignee, owner, repo, issue, user, author, to_mention):
         try:
             self.api_req(
@@ -111,6 +116,8 @@ def set_assignee(self, assignee, owner, repo, issue, user, author, to_mention):
         except urllib2.HTTPError, e:
             if e.code == 201:
                 pass
+            elif e.code == 400:
+                raise HttpClientError
             else:
                 raise e
 
@@ -146,6 +153,7 @@ def get_irc_nick(self, gh_name):
 
         return None
 
+    @retry(HttpClientError, delay=1, backoff=2, max_delay=3)
     def is_collaborator(self, commenter, owner, repo):
         """Returns True if `commenter` is a collaborator in the repo."""
         try:
@@ -156,6 +164,8 @@ def is_collaborator(self, commenter, owner, repo):
         except urllib2.HTTPError, e:
             if e.code == 404:
                 return False
+            elif e.code == 400:
+                raise HttpClientError
             else:
                 raise e
 
@@ -172,6 +182,7 @@ def post_warnings(self, diff, owner, repo, issue):
         if warnings:
             self.post_comment(warning_summary % '\n'.join(map(lambda x: '* ' + x, warnings)), owner, repo, issue)
 
+    @retry(HttpClientError, delay=1, backoff=2, max_delay=3)
     def post_comment(self, body, owner, repo, issue):
         try:
             self.api_req(
@@ -180,6 +191,8 @@ def post_comment(self, body, owner, repo, issue):
         except urllib2.HTTPError, e:
             if e.code == 201:
                 pass
+            elif e.code == 400:
+                raise HttpClientError
             else:
                 raise e
 
@@ -211,6 +224,7 @@ def unexpected_branch(self):
         return (expected_target, actual_target) \
             if expected_target != actual_target else False
 
+    @retry(HttpClientError, delay=1, backoff=2, max_delay=3)
     def is_new_contributor(self, username, owner, repo):
         # If this is a fork, we do not treat anyone as a new user. This is
         # because the API endpoint called in this function indicates all
@@ -227,6 +241,8 @@ def is_new_contributor(self, username, owner, repo):
         except urllib2.HTTPError, e:
             if e.code == 422:
                 return True
+            elif e.code == 400:
+                raise HttpClientError
             else:
                 raise e
 
diff --git a/setup.py b/setup.py
index 4e84a2e2..dbe64d19 100644
--- a/setup.py
+++ b/setup.py
@@ -9,4 +9,5 @@
       author_email='no-idea@no-server.no-suffix',
       url='https://github.com/rust-lang-nursery/highfive',
       packages=['highfive'],
+      install_requires=['retry'],
 )