diff --git a/lib/doorkeeper/config.rb b/lib/doorkeeper/config.rb
index 26771f7d7..277d427d0 100644
--- a/lib/doorkeeper/config.rb
+++ b/lib/doorkeeper/config.rb
@@ -113,9 +113,8 @@ def revoke_previous_authorization_code_token
         @config.instance_variable_set(:@revoke_previous_authorization_code_token, true)
       end
 
-      # Require non-confidential apps to use PKCE (send a code_challenge and
-      # code_verifier) when requesting an access_token using an authorization code
-      # (disabled by default)
+      # Require non-confidential apps to use PKCE (send a code_verifier) when requesting
+      # an access_token using an authorization code (disabled by default)
       def force_pkce
         @config.instance_variable_set(:@force_pkce, true)
       end
diff --git a/lib/doorkeeper/oauth/authorization_code_request.rb b/lib/doorkeeper/oauth/authorization_code_request.rb
index c5f7ac293..4043552ed 100644
--- a/lib/doorkeeper/oauth/authorization_code_request.rb
+++ b/lib/doorkeeper/oauth/authorization_code_request.rb
@@ -10,8 +10,8 @@ class AuthorizationCodeRequest < BaseRequest
       validate :redirect_uri, error: Errors::InvalidGrant
       validate :code_verifier, error: Errors::InvalidGrant
 
-      attr_reader :grant, :client, :redirect_uri, :access_token, :code_challenge,
-                  :code_verifier, :invalid_request_reason, :missing_param
+      attr_reader :grant, :client, :redirect_uri, :access_token, :code_verifier,
+                  :invalid_request_reason, :missing_param
 
       def initialize(server, grant, client, parameters = {})
         @server = server
@@ -67,8 +67,8 @@ def validate_params
         @missing_param =
           if grant&.uses_pkce? && code_verifier.blank?
             :code_verifier
-          elsif !confidential? && Doorkeeper.config.force_pkce? && code_challenge.blank?
-            :code_challenge
+          elsif !confidential? && Doorkeeper.config.force_pkce? && code_verifier.blank?
+            :code_verifier
           elsif redirect_uri.blank?
             :redirect_uri
           end