diff --git a/application/controllers/api/v1/Admins_api_v1.php b/application/controllers/api/v1/Admins_api_v1.php
index d751c120..5f15216b 100644
--- a/application/controllers/api/v1/Admins_api_v1.php
+++ b/application/controllers/api/v1/Admins_api_v1.php
@@ -37,7 +37,7 @@ class Admins_api_v1 extends EA_Controller
     /**
      * Get an admin collection.
      */
-    public function index()
+    public function index(): void
     {
         try {
             $keyword = $this->api->request_keyword();
@@ -79,7 +79,7 @@ class Admins_api_v1 extends EA_Controller
      *
      * @param int|null $id Admin ID.
      */
-    public function show(int $id = null)
+    public function show(int $id = null): void
     {
         try {
             $fields = $this->api->request_fields();
@@ -113,7 +113,7 @@ class Admins_api_v1 extends EA_Controller
     /**
      * Store a new admin.
      */
-    public function store()
+    public function store(): void
     {
         try {
             $admin = request();
@@ -145,7 +145,7 @@ class Admins_api_v1 extends EA_Controller
      *
      * @param int $id Admin ID.
      */
-    public function update(int $id)
+    public function update(int $id): void
     {
         try {
             $occurrences = $this->admins_model->get(['id' => $id]);
@@ -179,7 +179,7 @@ class Admins_api_v1 extends EA_Controller
      *
      * @param int $id Admin ID.
      */
-    public function destroy(int $id)
+    public function destroy(int $id): void
     {
         try {
             $occurrences = $this->admins_model->get(['id' => $id]);
diff --git a/application/controllers/api/v1/Appointments_api_v1.php b/application/controllers/api/v1/Appointments_api_v1.php
index 44cf4883..54e3c2d2 100644
--- a/application/controllers/api/v1/Appointments_api_v1.php
+++ b/application/controllers/api/v1/Appointments_api_v1.php
@@ -43,7 +43,7 @@ class Appointments_api_v1 extends EA_Controller
     /**
      * Get an appointment collection.
      */
-    public function index()
+    public function index(): void
     {
         try {
             $keyword = $this->api->request_keyword();
@@ -143,7 +143,7 @@ class Appointments_api_v1 extends EA_Controller
      *
      * @deprecated Since 1.5
      */
-    private function aggregates(array &$appointment)
+    private function aggregates(array &$appointment): void
     {
         $aggregates = request('aggregates') !== null;
 
@@ -171,7 +171,7 @@ class Appointments_api_v1 extends EA_Controller
      *
      * @param int|null $id Appointment ID.
      */
-    public function show(int $id = null)
+    public function show(int $id = null): void
     {
         try {
             $fields = $this->api->request_fields();
@@ -205,7 +205,7 @@ class Appointments_api_v1 extends EA_Controller
     /**
      * Store a new appointment.
      */
-    public function store()
+    public function store(): void
     {
         try {
             $appointment = request();
@@ -295,7 +295,7 @@ class Appointments_api_v1 extends EA_Controller
      *
      * @param int $id Appointment ID.
      */
-    public function update(int $id)
+    public function update(int $id): void
     {
         try {
             $occurrences = $this->appointments_model->get(['id' => $id]);
@@ -331,7 +331,7 @@ class Appointments_api_v1 extends EA_Controller
      *
      * @param int $id Appointment ID.
      */
-    public function destroy(int $id)
+    public function destroy(int $id): void
     {
         try {
             $occurrences = $this->appointments_model->get(['id' => $id]);
diff --git a/application/controllers/api/v1/Availabilities_api_v1.php b/application/controllers/api/v1/Availabilities_api_v1.php
index e0a87ec8..a696b52d 100644
--- a/application/controllers/api/v1/Availabilities_api_v1.php
+++ b/application/controllers/api/v1/Availabilities_api_v1.php
@@ -54,7 +54,7 @@ class Availabilities_api_v1 extends EA_Controller
      *
      * If no date parameter is provided then the current date will be used.
      */
-    public function get()
+    public function get(): void
     {
         try {
             $provider_id = request('providerId');
diff --git a/application/controllers/api/v1/Customers_api_v1.php b/application/controllers/api/v1/Customers_api_v1.php
index 693cc7b5..8f0b5fdd 100644
--- a/application/controllers/api/v1/Customers_api_v1.php
+++ b/application/controllers/api/v1/Customers_api_v1.php
@@ -35,7 +35,7 @@ class Customers_api_v1 extends EA_Controller
     /**
      * Get a customer collection.
      */
-    public function index()
+    public function index(): void
     {
         try {
             $keyword = $this->api->request_keyword();
@@ -77,7 +77,7 @@ class Customers_api_v1 extends EA_Controller
      *
      * @param int|null $id Customer ID.
      */
-    public function show(int $id = null)
+    public function show(int $id = null): void
     {
         try {
             $fields = $this->api->request_fields();
@@ -105,7 +105,7 @@ class Customers_api_v1 extends EA_Controller
     /**
      * Store a new customer.
      */
-    public function store()
+    public function store(): void
     {
         try {
             $customer = request();
@@ -133,7 +133,7 @@ class Customers_api_v1 extends EA_Controller
      *
      * @param int $id Customer ID.
      */
-    public function update(int $id)
+    public function update(int $id): void
     {
         try {
             $occurrences = $this->customers_model->get(['id' => $id]);
@@ -167,7 +167,7 @@ class Customers_api_v1 extends EA_Controller
      *
      * @param int $id Customer ID.
      */
-    public function destroy(int $id)
+    public function destroy(int $id): void
     {
         try {
             $occurrences = $this->customers_model->get(['id' => $id]);
diff --git a/application/controllers/api/v1/Providers_api_v1.php b/application/controllers/api/v1/Providers_api_v1.php
index 916942b9..5613fa40 100644
--- a/application/controllers/api/v1/Providers_api_v1.php
+++ b/application/controllers/api/v1/Providers_api_v1.php
@@ -35,7 +35,7 @@ class Providers_api_v1 extends EA_Controller
     /**
      * Get a provider collection.
      */
-    public function index()
+    public function index(): void
     {
         try {
             $keyword = $this->api->request_keyword();
@@ -77,7 +77,7 @@ class Providers_api_v1 extends EA_Controller
      *
      * @param int|null $id Provider ID.
      */
-    public function show(int $id = null)
+    public function show(int $id = null): void
     {
         try {
             $fields = $this->api->request_fields();
@@ -111,7 +111,7 @@ class Providers_api_v1 extends EA_Controller
     /**
      * Store a new provider.
      */
-    public function store()
+    public function store(): void
     {
         try {
             $provider = request();
@@ -151,7 +151,7 @@ class Providers_api_v1 extends EA_Controller
      *
      * @param int $id Provider ID.
      */
-    public function update(int $id)
+    public function update(int $id): void
     {
         try {
             $occurrences = $this->providers_model->get(['id' => $id]);
@@ -185,7 +185,7 @@ class Providers_api_v1 extends EA_Controller
      *
      * @param int $id Provider ID.
      */
-    public function destroy(int $id)
+    public function destroy(int $id): void
     {
         try {
             $occurrences = $this->providers_model->get(['id' => $id]);
diff --git a/application/controllers/api/v1/Secretaries_api_v1.php b/application/controllers/api/v1/Secretaries_api_v1.php
index 9d151565..7ff4c8c4 100644
--- a/application/controllers/api/v1/Secretaries_api_v1.php
+++ b/application/controllers/api/v1/Secretaries_api_v1.php
@@ -35,7 +35,7 @@ class Secretaries_api_v1 extends EA_Controller
     /**
      * Get a secretary collection.
      */
-    public function index()
+    public function index(): void
     {
         try {
             $keyword = $this->api->request_keyword();
@@ -77,7 +77,7 @@ class Secretaries_api_v1 extends EA_Controller
      *
      * @param int|null $id Secretary ID.
      */
-    public function show(int $id = null)
+    public function show(int $id = null): void
     {
         try {
             $fields = $this->api->request_fields();
@@ -105,7 +105,7 @@ class Secretaries_api_v1 extends EA_Controller
     /**
      * Store a new secretary.
      */
-    public function store()
+    public function store(): void
     {
         try {
             $secretary = request();
@@ -141,7 +141,7 @@ class Secretaries_api_v1 extends EA_Controller
      *
      * @param int $id Secretary ID.
      */
-    public function update(int $id)
+    public function update(int $id): void
     {
         try {
             $occurrences = $this->secretaries_model->get(['id' => $id]);
@@ -175,7 +175,7 @@ class Secretaries_api_v1 extends EA_Controller
      *
      * @param int $id Secretary ID.
      */
-    public function destroy(int $id)
+    public function destroy(int $id): void
     {
         try {
             $occurrences = $this->secretaries_model->get(['id' => $id]);
diff --git a/application/controllers/api/v1/Service_categories_api_v1.php b/application/controllers/api/v1/Service_categories_api_v1.php
index c8c84481..c0b288f9 100644
--- a/application/controllers/api/v1/Service_categories_api_v1.php
+++ b/application/controllers/api/v1/Service_categories_api_v1.php
@@ -35,7 +35,7 @@ class Service_categories_api_v1 extends EA_Controller
     /**
      * Get a service-category collection.
      */
-    public function index()
+    public function index(): void
     {
         try {
             $keyword = $this->api->request_keyword();
@@ -77,7 +77,7 @@ class Service_categories_api_v1 extends EA_Controller
      *
      * @param int|null $id Service-category ID.
      */
-    public function show(int $id = null)
+    public function show(int $id = null): void
     {
         try {
             $fields = $this->api->request_fields();
@@ -111,7 +111,7 @@ class Service_categories_api_v1 extends EA_Controller
     /**
      * Store a new service-category.
      */
-    public function store()
+    public function store(): void
     {
         try {
             $service_category = request();
@@ -139,7 +139,7 @@ class Service_categories_api_v1 extends EA_Controller
      *
      * @param int $id Service-category ID.
      */
-    public function update(int $id)
+    public function update(int $id): void
     {
         try {
             $occurrences = $this->service_categories_model->get(['id' => $id]);
@@ -173,7 +173,7 @@ class Service_categories_api_v1 extends EA_Controller
      *
      * @param int $id Service-category ID.
      */
-    public function destroy(int $id)
+    public function destroy(int $id): void
     {
         try {
             $occurrences = $this->service_categories_model->get(['id' => $id]);
diff --git a/application/controllers/api/v1/Services_api_v1.php b/application/controllers/api/v1/Services_api_v1.php
index fa6f250d..47eaa7cd 100644
--- a/application/controllers/api/v1/Services_api_v1.php
+++ b/application/controllers/api/v1/Services_api_v1.php
@@ -35,7 +35,7 @@ class Services_api_v1 extends EA_Controller
     /**
      * Get an service collection.
      */
-    public function index()
+    public function index(): void
     {
         try {
             $keyword = $this->api->request_keyword();
@@ -77,7 +77,7 @@ class Services_api_v1 extends EA_Controller
      *
      * @param int|null $id Service ID.
      */
-    public function show(int $id = null)
+    public function show(int $id = null): void
     {
         try {
             $fields = $this->api->request_fields();
@@ -111,7 +111,7 @@ class Services_api_v1 extends EA_Controller
     /**
      * Store a new service.
      */
-    public function store()
+    public function store(): void
     {
         try {
             $service = request();
@@ -139,7 +139,7 @@ class Services_api_v1 extends EA_Controller
      *
      * @param int $id Service ID.
      */
-    public function update(int $id)
+    public function update(int $id): void
     {
         try {
             $occurrences = $this->services_model->get(['id' => $id]);
@@ -173,7 +173,7 @@ class Services_api_v1 extends EA_Controller
      *
      * @param int $id Service ID.
      */
-    public function destroy(int $id)
+    public function destroy(int $id): void
     {
         try {
             $occurrences = $this->services_model->get(['id' => $id]);
diff --git a/application/controllers/api/v1/Settings_api_v1.php b/application/controllers/api/v1/Settings_api_v1.php
index 177757f6..e32f237c 100644
--- a/application/controllers/api/v1/Settings_api_v1.php
+++ b/application/controllers/api/v1/Settings_api_v1.php
@@ -71,7 +71,7 @@ class Settings_api_v1 extends EA_Controller
      *
      * @param string $name Setting name.
      */
-    public function show(string $name)
+    public function show(string $name): void
     {
         try {
             $value = setting($name);
@@ -90,7 +90,7 @@ class Settings_api_v1 extends EA_Controller
      *
      * @param string $name Setting name.
      */
-    public function update(string $name)
+    public function update(string $name): void
     {
         try {
             $value = request('value');
diff --git a/application/controllers/api/v1/Unavailabilities_api_v1.php b/application/controllers/api/v1/Unavailabilities_api_v1.php
index dbf304bd..0c6d7bc8 100644
--- a/application/controllers/api/v1/Unavailabilities_api_v1.php
+++ b/application/controllers/api/v1/Unavailabilities_api_v1.php
@@ -35,7 +35,7 @@ class Unavailabilities_api_v1 extends EA_Controller
     /**
      * Get an unavailability collection.
      */
-    public function index()
+    public function index(): void
     {
         try {
             $keyword = $this->api->request_keyword();
@@ -77,7 +77,7 @@ class Unavailabilities_api_v1 extends EA_Controller
      *
      * @param int|null $id Unavailability ID.
      */
-    public function show(int $id = null)
+    public function show(int $id = null): void
     {
         try {
             $fields = $this->api->request_fields();
@@ -111,7 +111,7 @@ class Unavailabilities_api_v1 extends EA_Controller
     /**
      * Store a new unavailability.
      */
-    public function store()
+    public function store(): void
     {
         try {
             $unavailability = request();
@@ -139,7 +139,7 @@ class Unavailabilities_api_v1 extends EA_Controller
      *
      * @param int $id Unavailability ID.
      */
-    public function update(int $id)
+    public function update(int $id): void
     {
         try {
             $occurrences = $this->unavailabilities_model->get(['id' => $id]);
@@ -173,7 +173,7 @@ class Unavailabilities_api_v1 extends EA_Controller
      *
      * @param int $id Unavailability ID.
      */
-    public function destroy(int $id)
+    public function destroy(int $id): void
     {
         try {
             $occurrences = $this->unavailabilities_model->get(['id' => $id]);
diff --git a/application/controllers/api/v1/Webhooks_api_v1.php b/application/controllers/api/v1/Webhooks_api_v1.php
index b7baa954..e1e019f6 100644
--- a/application/controllers/api/v1/Webhooks_api_v1.php
+++ b/application/controllers/api/v1/Webhooks_api_v1.php
@@ -35,7 +35,7 @@ class Webhooks_api_v1 extends EA_Controller
     /**
      * Get a webhook collection.
      */
-    public function index()
+    public function index(): void
     {
         try {
             $keyword = $this->api->request_keyword();
@@ -77,7 +77,7 @@ class Webhooks_api_v1 extends EA_Controller
      *
      * @param int|null $id Webhook ID.
      */
-    public function show(int $id = null)
+    public function show(int $id = null): void
     {
         try {
             $fields = $this->api->request_fields();
@@ -111,7 +111,7 @@ class Webhooks_api_v1 extends EA_Controller
     /**
      * Store a new webhook.
      */
-    public function store()
+    public function store(): void
     {
         try {
             $webhook = request();
@@ -139,7 +139,7 @@ class Webhooks_api_v1 extends EA_Controller
      *
      * @param int $id Webhook ID.
      */
-    public function update(int $id)
+    public function update(int $id): void
     {
         try {
             $occurrences = $this->webhooks_model->get(['id' => $id]);
@@ -173,7 +173,7 @@ class Webhooks_api_v1 extends EA_Controller
      *
      * @param int $id Webhook ID.
      */
-    public function destroy(int $id)
+    public function destroy(int $id): void
     {
         try {
             $occurrences = $this->webhooks_model->get(['id' => $id]);