diff --git a/src/Contracts/ResultInterface.php b/src/Contracts/ResultInterface.php
index e8961e3..fcb791b 100644
--- a/src/Contracts/ResultInterface.php
+++ b/src/Contracts/ResultInterface.php
@@ -257,5 +257,5 @@ public function deviceModel(): string;
      *
      * @return array
      */
-    public function toArray();
+    public function toArray(): array;
 }
diff --git a/src/Result.php b/src/Result.php
index e3c882a..efd2b2c 100644
--- a/src/Result.php
+++ b/src/Result.php
@@ -459,7 +459,7 @@ public function jsonSerialize(): array
     /**
      * @inheritdoc
      */
-    public function toArray()
+    public function toArray(): array
     {
         return get_object_vars($this);
     }
diff --git a/src/Stages/DeviceDetector.php b/src/Stages/DeviceDetector.php
index 9d35ba9..2324a71 100644
--- a/src/Stages/DeviceDetector.php
+++ b/src/Stages/DeviceDetector.php
@@ -91,7 +91,7 @@ public function __invoke(PayloadInterface $payload): PayloadInterface
      * @param  string $prefix
      * @return array
      */
-    protected function parseVersion(string $version, string $prefix)
+    protected function parseVersion(string $version, string $prefix): array
     {
         $response = [];