diff --git a/Gemfile b/Gemfile
index 92b69782e..baefffb2f 100644
--- a/Gemfile
+++ b/Gemfile
@@ -46,7 +46,7 @@ gem 'omniauth-rails_csrf_protection', '~> 0.1'
 
 gem 'color_diff', '~> 0.1'
 gem 'discard', '~> 1.2'
-gem 'doorkeeper', '~> 5.5'
+gem 'doorkeeper', '~> 5.6'
 gem 'ed25519', '~> 1.3'
 gem 'fast_blank', '~> 1.0'
 gem 'fastimage'
diff --git a/Gemfile.lock b/Gemfile.lock
index 0c6aea49b..2caa5f2e1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -207,7 +207,7 @@ GEM
     docile (1.3.4)
     domain_name (0.5.20190701)
       unf (>= 0.0.5, < 1.0.0)
-    doorkeeper (5.5.4)
+    doorkeeper (5.6.0)
       railties (>= 5)
     dotenv (2.8.1)
     dotenv-rails (2.8.1)
@@ -761,7 +761,7 @@ DEPENDENCIES
   devise-two-factor (~> 4.0)
   devise_pam_authenticatable2 (~> 9.2)
   discard (~> 1.2)
-  doorkeeper (~> 5.5)
+  doorkeeper (~> 5.6)
   dotenv-rails (~> 2.8)
   ed25519 (~> 1.3)
   fabrication (~> 2.30)