diff --git a/dyndnsd.gemspec b/dyndnsd.gemspec
index 8f5e2a9..19fe0d8 100644
--- a/dyndnsd.gemspec
+++ b/dyndnsd.gemspec
@@ -39,6 +39,6 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'rack-test'
   s.add_development_dependency 'rake'
   s.add_development_dependency 'rspec'
-  s.add_development_dependency 'rubocop', '~> 0.82.0'
+  s.add_development_dependency 'rubocop', '~> 0.88.0'
   s.add_development_dependency 'solargraph'
 end
diff --git a/lib/dyndnsd/responder/dyndns_style.rb b/lib/dyndnsd/responder/dyndns_style.rb
index 284e1e2..1a4f514 100644
--- a/lib/dyndnsd/responder/dyndns_style.rb
+++ b/lib/dyndnsd/responder/dyndns_style.rb
@@ -27,9 +27,10 @@ module Dyndnsd
       # @param body [Array{String}]
       # @return [Array{Integer,Hash{String => String},Array{String}}]
       def decorate_dyndnsd_response(status_code, headers, body)
-        if status_code == 200
+        case status_code
+        when 200
           [200, {'Content-Type' => 'text/plain'}, [get_success_body(body[0], body[1])]]
-        elsif status_code == 422
+        when 422
           error_response_map[headers['X-DynDNS-Response']]
         end
       end
@@ -39,9 +40,10 @@ module Dyndnsd
       # @param _body [Array{String}]
       # @return [Array{Integer,Hash{String => String},Array{String}}]
       def decorate_other_response(status_code, headers, _body)
-        if status_code == 400
+        case status_code
+        when 400
           [status_code, headers, ['Bad Request']]
-        elsif status_code == 401
+        when 401
           [status_code, headers, ['badauth']]
         end
       end
diff --git a/lib/dyndnsd/responder/rest_style.rb b/lib/dyndnsd/responder/rest_style.rb
index e60e95a..8687259 100644
--- a/lib/dyndnsd/responder/rest_style.rb
+++ b/lib/dyndnsd/responder/rest_style.rb
@@ -27,9 +27,10 @@ module Dyndnsd
       # @param body [Array{String}]
       # @return [Array{Integer,Hash{String => String},Array{String}}]
       def decorate_dyndnsd_response(status_code, headers, body)
-        if status_code == 200
+        case status_code
+        when 200
           [200, {'Content-Type' => 'text/plain'}, [get_success_body(body[0], body[1])]]
-        elsif status_code == 422
+        when 422
           error_response_map[headers['X-DynDNS-Response']]
         end
       end
@@ -39,9 +40,10 @@ module Dyndnsd
       # @param _body [Array{String}]
       # @return [Array{Integer,Hash{String => String},Array{String}}]
       def decorate_other_response(status_code, headers, _body)
-        if status_code == 400
+        case status_code
+        when 400
           [status_code, headers, ['Bad Request']]
-        elsif status_code == 401
+        when 401
           [status_code, headers, ['Unauthorized']]
         end
       end