diff --git a/Gemfile b/Gemfile
index de6dda4..fe141e6 100644
--- a/Gemfile
+++ b/Gemfile
@@ -10,7 +10,7 @@ gem 'oauth2', '~> 1.0'
 gem 'gocardless_pro', path: './vendor/gocardless_pro'
 gem 'rack', '~> 1.6.4'
 gem 'json_schema', '~> 0.7'
-gem 'sequel', '~> 4.27'
+gem 'sequel', '~> 5.18'
 gem 'mail', '~> 2.6.3'
 gem 'hamster', github: 'hamstergem/hamster'
 gem 'rake', '~> 10.4.2'
diff --git a/Gemfile.lock b/Gemfile.lock
index cd1b635..2092e1c 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -17,7 +17,7 @@ GIT
       concurrent-ruby (~> 1.0)
 
 PATH
-  remote: ./vendor/gocardless_pro
+  remote: vendor/gocardless_pro
   specs:
     gocardless_pro (1.0.2)
       faraday (>= 0.8.9, < 0.10)
@@ -142,7 +142,7 @@ GEM
     rspec-support (3.4.1)
     ruby-progressbar (1.7.5)
     safe_yaml (1.0.4)
-    sequel (4.29.0)
+    sequel (5.18.0)
     slop (3.6.0)
     sqlite3 (1.3.11)
     thread_safe (0.3.5)
@@ -181,7 +181,7 @@ DEPENDENCIES
   rantly (~> 0.3.2)
   rspec (~> 3.3)
   rubocop!
-  sequel (~> 4.27)
+  sequel (~> 5.18)
   sqlite3 (~> 1.3)
   webmock (~> 1.22)