diff --git a/.env.production.sample b/.env.production.sample
index 05a043256..b96754e78 100644
--- a/.env.production.sample
+++ b/.env.production.sample
@@ -159,7 +159,7 @@ STREAMING_CLUSTER_NUM=1
 # PAM_DEFAULT_SUFFIX=pam
 # Name of the pam service (pam "auth" section is evaluated)
 # PAM_DEFAULT_SERVICE=rpam
-# Name of the pam service used for checking if an user can register (pam "account" section is evaluated)
+# Name of the pam service used for checking if an user can register (pam "account" section is evaluated) (nil (disabled) by default)
 # PAM_CONTROLLED_SERVICE=rpam
 
 # Global OAuth settings (optional) :
diff --git a/config/initializers/devise.rb b/config/initializers/devise.rb
index 0dc202976..df45dcd1f 100644
--- a/config/initializers/devise.rb
+++ b/config/initializers/devise.rb
@@ -344,7 +344,7 @@ Devise.setup do |config|
     config.check_at_sign          = true
     config.pam_default_suffix     = ENV.fetch('PAM_DEFAULT_SUFFIX') { nil }
     config.pam_default_service    = ENV.fetch('PAM_DEFAULT_SERVICE') { 'rpam' }
-    config.pam_controlled_service = ENV.fetch('PAM_CONTROLLED_SERVICE') { 'rpam' }
+    config.pam_controlled_service = ENV.fetch('PAM_CONTROLLED_SERVICE') { nil }
   end
 
   if ENV['LDAP_ENABLED'] == 'true'