diff --git a/manifests/api.pp b/manifests/api.pp
index 137e1f1..4bf44cf 100644
--- a/manifests/api.pp
+++ b/manifests/api.pp
@@ -74,7 +74,7 @@
 #
 # [*watcher_client_project_name*]
 #   (Optional) Service project name.
-#   Defaults to 'service'
+#   Defaults to 'services'
 #
 # [*watcher_client_certfile*]
 #   (Optional) PEM encoded client certificate cert file.
@@ -154,7 +154,7 @@ class watcher::api (
   $watcher_api_workers                = $::os_workers,
   $watcher_api_enable_ssl_api         = $::os_service_default,
   $watcher_client_default_domain_name = $::os_service_default,
-  $watcher_client_project_name        = 'service',
+  $watcher_client_project_name        = 'services',
   $watcher_client_certfile            = $::os_service_default,
   $watcher_client_cafile              = $::os_service_default,
   $watcher_client_project_domain_name = $::os_service_default,
diff --git a/releasenotes/notes/update_watcher_client_project_name-abd703bec044d78d.yaml b/releasenotes/notes/update_watcher_client_project_name-abd703bec044d78d.yaml
new file mode 100644
index 0000000..69c33aa
--- /dev/null
+++ b/releasenotes/notes/update_watcher_client_project_name-abd703bec044d78d.yaml
@@ -0,0 +1,4 @@
+---
+upgrade:
+  - The default value for watcher::api::watcher_client_project_name is
+    changed to 'services'.
diff --git a/spec/classes/watcher_api_spec.rb b/spec/classes/watcher_api_spec.rb
index 812017d..fcbf2bf 100644
--- a/spec/classes/watcher_api_spec.rb
+++ b/spec/classes/watcher_api_spec.rb
@@ -95,7 +95,7 @@ describe 'watcher::api' do
         is_expected.to contain_watcher_config('watcher_clients_auth/password').with_value( params[:watcher_client_password] )
         is_expected.to contain_watcher_config('watcher_clients_auth/auth_url').with_value('http://localhost:5000/')
         is_expected.to contain_watcher_config('watcher_clients_auth/auth_uri').with_value('http://localhost:5000/')
-        is_expected.to contain_watcher_config('watcher_clients_auth/project_name').with_value('service')
+        is_expected.to contain_watcher_config('watcher_clients_auth/project_name').with_value('services')
         is_expected.to contain_watcher_config('watcher_clients_auth/project_domain_name').with_value('<SERVICE DEFAULT>')
         is_expected.to contain_watcher_config('watcher_clients_auth/user_domain_name').with_value('<SERVICE DEFAULT>')
         is_expected.to contain_watcher_config('watcher_clients_auth/insecure').with_value('<SERVICE DEFAULT>')