diff --git a/src/Jeeves/Generators/Crud/Interfaces/Model.php b/src/Jeeves/Generators/Crud/Interfaces/Model.php
index 2e0b118..77d6513 100644
--- a/src/Jeeves/Generators/Crud/Interfaces/Model.php
+++ b/src/Jeeves/Generators/Crud/Interfaces/Model.php
@@ -17,6 +17,7 @@ public function genModelInterface(
         bool $withStore = false,
         string $phpVersion = PHP_VERSION
     ): PhpNamespace {
+        $hasTypedConst = $this->hasTypedConst($phpVersion);
         $namespace = new PhpNamespace($rootNamespace . '\Api\Data');
         $interface = $namespace->addInterface($className);
 
@@ -27,7 +28,10 @@ public function genModelInterface(
         if ($cacheTag !== null) {
             $namespace->addUse('\Magento\Framework\DataObject\IdentityInterface');
             $interface->setExtends('\Magento\Framework\DataObject\IdentityInterface');
-            $interface->addConstant('CACHE_TAG', $cacheTag)->setVisibility('public');
+            $ctag = $interface->addConstant('CACHE_TAG', $cacheTag)->setVisibility('public');
+            if ($hasTypedConst) {
+                $ctag->setType('string');
+            }
         }
 
         if ($withStore) {
@@ -48,7 +52,10 @@ public function genModelInterface(
             if (isset($value['identity']) && $value['identity'] === true) {
                 $generated = true;
             }
-            $interface->addConstant(strtoupper($name), strtolower($name))->setPublic();
+            $c = $interface->addConstant(strtoupper($name), strtolower($name))->setPublic();
+            if ($hasTypedConst) {
+                $c->setType('string');
+            }
             $method = $this->snakeCaseToUpperCamelCase($name);
             $get = $interface->addMethod('get' . $method)
                 ->setVisibility('public');
diff --git a/test/Expectations/Crud/83/v1/Api/Data/CardInterface.php b/test/Expectations/Crud/83/v1/Api/Data/CardInterface.php
index 111e604..0ba7398 100644
--- a/test/Expectations/Crud/83/v1/Api/Data/CardInterface.php
+++ b/test/Expectations/Crud/83/v1/Api/Data/CardInterface.php
@@ -9,13 +9,13 @@
  */
 interface CardInterface extends IdentityInterface
 {
-    public const CACHE_TAG = 'samp_card';
-    public const CARD_ID = 'card_id';
-    public const TITLE = 'title';
-    public const CODE = 'code';
-    public const CATEGORY_ID = 'category_id';
-    public const IS_ACTIVE = 'is_active';
-    public const STORE_ID = 'store_id';
+    public const string CACHE_TAG = 'samp_card';
+    public const string CARD_ID = 'card_id';
+    public const string TITLE = 'title';
+    public const string CODE = 'code';
+    public const string CATEGORY_ID = 'category_id';
+    public const string IS_ACTIVE = 'is_active';
+    public const string STORE_ID = 'store_id';
 
     /**
      * Get card id
diff --git a/test/Expectations/Crud/83/v1/Api/Data/CartItemInterface.php b/test/Expectations/Crud/83/v1/Api/Data/CartItemInterface.php
index ca9f252..a1c43de 100644
--- a/test/Expectations/Crud/83/v1/Api/Data/CartItemInterface.php
+++ b/test/Expectations/Crud/83/v1/Api/Data/CartItemInterface.php
@@ -4,16 +4,16 @@
 
 interface CartItemInterface
 {
-    public const CART_ID = 'cart_id';
-    public const IS_ACTIVE = 'is_active';
-    public const DELIVERY_DATE = 'delivery_date';
-    public const CITY = 'city';
-    public const CUSTOMER_GROUP = 'customer_group';
-    public const DESCRIPTION = 'description';
-    public const CREATED_AT = 'created_at';
-    public const UPDATED_AT = 'updated_at';
-    public const DISCOUNT = 'discount';
-    public const PRICE = 'price';
+    public const string CART_ID = 'cart_id';
+    public const string IS_ACTIVE = 'is_active';
+    public const string DELIVERY_DATE = 'delivery_date';
+    public const string CITY = 'city';
+    public const string CUSTOMER_GROUP = 'customer_group';
+    public const string DESCRIPTION = 'description';
+    public const string CREATED_AT = 'created_at';
+    public const string UPDATED_AT = 'updated_at';
+    public const string DISCOUNT = 'discount';
+    public const string PRICE = 'price';
 
     /**
      * Get cart id
diff --git a/test/Expectations/Crud/83/v1/Api/Data/ColumnsInterface.php b/test/Expectations/Crud/83/v1/Api/Data/ColumnsInterface.php
index c405527..e9b3745 100644
--- a/test/Expectations/Crud/83/v1/Api/Data/ColumnsInterface.php
+++ b/test/Expectations/Crud/83/v1/Api/Data/ColumnsInterface.php
@@ -4,17 +4,17 @@
 
 interface ColumnsInterface
 {
-    public const ID = 'id';
-    public const IS_ACTIVE = 'is_active';
-    public const HAS_FLAG = 'has_flag';
-    public const MERGE_DATE = 'merge_date';
-    public const DISCOUNT = 'discount';
-    public const COST = 'cost';
-    public const PRICE = 'price';
-    public const NAME = 'name';
-    public const DESCRIPTION = 'description';
-    public const CREATED_AT = 'created_at';
-    public const UPDATED_AT = 'updated_at';
+    public const string ID = 'id';
+    public const string IS_ACTIVE = 'is_active';
+    public const string HAS_FLAG = 'has_flag';
+    public const string MERGE_DATE = 'merge_date';
+    public const string DISCOUNT = 'discount';
+    public const string COST = 'cost';
+    public const string PRICE = 'price';
+    public const string NAME = 'name';
+    public const string DESCRIPTION = 'description';
+    public const string CREATED_AT = 'created_at';
+    public const string UPDATED_AT = 'updated_at';
 
     /**
      * Get id
diff --git a/test/Expectations/Crud/83/v1/Api/Data/PosterInterface.php b/test/Expectations/Crud/83/v1/Api/Data/PosterInterface.php
index f2cc4fb..41836d2 100644
--- a/test/Expectations/Crud/83/v1/Api/Data/PosterInterface.php
+++ b/test/Expectations/Crud/83/v1/Api/Data/PosterInterface.php
@@ -9,13 +9,13 @@
  */
 interface PosterInterface extends IdentityInterface
 {
-    public const CACHE_TAG = 'samp_poster';
-    public const ID = 'id';
-    public const NAME = 'name';
-    public const SUBNAME = 'subname';
-    public const FAMILY = 'family';
-    public const IS_ACTIVE = 'is_active';
-    public const PRODUCT_ID = 'product_id';
+    public const string CACHE_TAG = 'samp_poster';
+    public const string ID = 'id';
+    public const string NAME = 'name';
+    public const string SUBNAME = 'subname';
+    public const string FAMILY = 'family';
+    public const string IS_ACTIVE = 'is_active';
+    public const string PRODUCT_ID = 'product_id';
 
     /**
      * Get id
diff --git a/test/Expectations/Crud/83/v1/Api/Data/TicketInterface.php b/test/Expectations/Crud/83/v1/Api/Data/TicketInterface.php
index 1326fa3..3ea0569 100644
--- a/test/Expectations/Crud/83/v1/Api/Data/TicketInterface.php
+++ b/test/Expectations/Crud/83/v1/Api/Data/TicketInterface.php
@@ -4,9 +4,9 @@
 
 interface TicketInterface
 {
-    public const TICKET_ID = 'ticket_id';
-    public const NAME = 'name';
-    public const IS_ACTIVE = 'is_active';
+    public const string TICKET_ID = 'ticket_id';
+    public const string NAME = 'name';
+    public const string IS_ACTIVE = 'is_active';
 
     /**
      * Get ticket id