diff --git a/Gemfile b/Gemfile
index 13b0e524..c38aad67 100644
--- a/Gemfile
+++ b/Gemfile
@@ -15,7 +15,10 @@ gem "faraday-cookie_jar", "~> 0.0.6"
 
 gem "govuk_sidekiq", "~> 3.0"
 gem "sidekiq-scheduler", "~> 2.2"
-gem "sidekiq-unique-jobs", "~> 5.0"
+# We can't use v5 of this because it requires redis 3 and we use 2.8
+# We use our own fork because the latest 4.x release has a bug with
+# removing jobs from the uniquejobs hash in redis
+gem "sidekiq-unique-jobs", git: "https://github.com/alphagov/sidekiq-unique-jobs", require: false
 
 gem "activerecord-import", "~> 0.22"
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 97f79f47..442153b5 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,3 +1,11 @@
+GIT
+  remote: https://github.com/alphagov/sidekiq-unique-jobs
+  revision: 6c03e39c3ad6ba1468d567c22bb99908f6fdb317
+  specs:
+    sidekiq-unique-jobs (4.0.18)
+      sidekiq (>= 2.6)
+      thor
+
 GEM
   remote: https://rubygems.org/
   specs:
@@ -283,9 +291,6 @@ GEM
       activesupport
       sidekiq (>= 2.6)
       statsd-ruby (>= 1.1.0)
-    sidekiq-unique-jobs (5.0.10)
-      sidekiq (>= 4.0, <= 6.0)
-      thor (~> 0)
     simplecov (0.15.1)
       docile (~> 1.1.0)
       json (>= 1.8, < 3)
@@ -357,7 +362,7 @@ DEPENDENCIES
   rspec-rails (~> 3.4)
   rspec-sidekiq (~> 3.0)
   sidekiq-scheduler (~> 2.2)
-  sidekiq-unique-jobs (~> 5.0)
+  sidekiq-unique-jobs!
   simplecov (~> 0.11)
   simplecov-rcov (~> 0.2)
   sqlite3
@@ -366,4 +371,4 @@ DEPENDENCIES
   webmock
 
 BUNDLED WITH
-   1.16.0
+   1.16.1