diff --git a/Gemfile b/Gemfile
index bde2d2f..0c8aa43 100644
--- a/Gemfile
+++ b/Gemfile
@@ -55,7 +55,7 @@ gem 'device_detector'
 
 # OAuth 2 provider for Ruby on Rails / Grape.
 # https://github.com/doorkeeper-gem/doorkeeper
-gem 'doorkeeper', '~> 5.2.5'
+gem 'doorkeeper', '~> 5.6.6'
 
 # Fishes out the Accept-Language header into an array.
 # https://github.com/iain/http_accept_language
diff --git a/Gemfile.lock b/Gemfile.lock
index a64ba29..b9e5a29 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -91,7 +91,7 @@ GEM
     coderay (1.1.3)
     coercible (1.0.0)
       descendants_tracker (~> 0.0.1)
-    concurrent-ruby (1.1.10)
+    concurrent-ruby (1.2.2)
     connection_pool (2.2.5)
     content_disposition (1.0.0)
     crack (0.4.5)
@@ -114,7 +114,7 @@ GEM
       warden (~> 1.2.3)
     diff-lcs (1.5.0)
     docile (1.4.0)
-    doorkeeper (5.2.6)
+    doorkeeper (5.6.6)
       railties (>= 5)
     dotenv (2.7.6)
     dotenv-rails (2.7.6)
@@ -155,7 +155,7 @@ GEM
       dry-initializer (~> 3.0)
       dry-schema (~> 1.9, >= 1.9.1)
     equalizer (0.0.11)
-    erubi (1.10.0)
+    erubi (1.12.0)
     et-orbi (1.2.7)
       tzinfo
     factory_bot (6.2.1)
@@ -187,7 +187,7 @@ GEM
       activesupport (>= 5.0)
     hashdiff (1.0.1)
     http_accept_language (2.1.1)
-    i18n (1.12.0)
+    i18n (1.14.1)
       concurrent-ruby (~> 1.0)
     ice_nine (0.11.2)
     jmespath (1.6.1)
@@ -212,25 +212,25 @@ GEM
     listen (3.0.8)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
-    loofah (2.19.1)
+    loofah (2.21.3)
       crass (~> 1.0.2)
-      nokogiri (>= 1.5.9)
+      nokogiri (>= 1.12.0)
     mail (2.7.1)
       mini_mime (>= 0.1.1)
     marcel (1.0.2)
     method_source (1.0.0)
     mini_mime (1.1.2)
-    minitest (5.17.0)
+    minitest (5.18.0)
     msgpack (1.5.1)
     multi_json (1.15.0)
     multi_xml (0.6.0)
     mustache (1.1.1)
     nio4r (2.5.8)
-    nokogiri (1.13.10-arm64-darwin)
+    nokogiri (1.15.2-arm64-darwin)
       racc (~> 1.4)
-    nokogiri (1.13.10-x86_64-darwin)
+    nokogiri (1.15.2-x86_64-darwin)
       racc (~> 1.4)
-    nokogiri (1.13.10-x86_64-linux)
+    nokogiri (1.15.2-x86_64-linux)
       racc (~> 1.4)
     oauth2 (1.4.9)
       faraday (>= 0.17.3, < 3.0)
@@ -258,14 +258,14 @@ GEM
     puma (5.6.4)
       nio4r (~> 2.0)
     raabro (1.4.0)
-    racc (1.6.1)
-    rack (2.2.6.4)
+    racc (1.7.0)
+    rack (2.2.7)
     rack-attack (6.6.1)
       rack (>= 1.0, < 3)
     rack-cors (1.1.1)
       rack (>= 2.0.0)
-    rack-test (1.1.0)
-      rack (>= 1.0, < 3)
+    rack-test (2.1.0)
+      rack (>= 1.3)
     rack-timeout (0.6.0)
     rails (5.2.8)
       actioncable (= 5.2.8)
@@ -283,8 +283,9 @@ GEM
     rails-dom-testing (2.0.3)
       activesupport (>= 4.2.0)
       nokogiri (>= 1.6)
-    rails-html-sanitizer (1.4.4)
-      loofah (~> 2.19, >= 2.19.1)
+    rails-html-sanitizer (1.6.0)
+      loofah (~> 2.21)
+      nokogiri (~> 1.14)
     rails-settings-cached (0.7.2)
       rails (>= 4.2.0)
     railties (5.2.8)
@@ -435,11 +436,11 @@ GEM
     sys-filesystem (1.4.3)
       ffi (~> 1.1)
     test-prof (1.0.9)
-    thor (1.2.1)
+    thor (1.2.2)
     thread_safe (0.3.6)
     tilt (2.0.10)
     tty-which (0.4.2)
-    tzinfo (1.2.10)
+    tzinfo (1.2.11)
       thread_safe (~> 0.1)
     unicode-display_width (2.1.0)
     uniform_notifier (1.16.0)
@@ -479,7 +480,7 @@ DEPENDENCIES
   database_cleaner
   device_detector
   devise (>= 4.7.1)
-  doorkeeper (~> 5.2.5)
+  doorkeeper (~> 5.6.6)
   dotenv-rails
   dry-validation (>= 1.3.0)
   factory_bot_rails