diff --git a/src/JsonObjectBuilder.php b/src/JsonObjectBuilder.php
index 82078f0..ff07cfd 100644
--- a/src/JsonObjectBuilder.php
+++ b/src/JsonObjectBuilder.php
@@ -17,6 +17,9 @@ public function fromJsonString(string $jsonString):JsonObject {
 		return $this->fromJsonDecoded($json);
 	}
 
+	/**
+	 * @param object|array<mixed>|string|int|float|bool|null $jsonDecoded
+	 */
 	public function fromJsonDecoded(
 		object|array|string|int|float|bool|null $jsonDecoded
 	):JsonObject {
@@ -68,4 +71,4 @@ public function fromJsonDecoded(
 
 		return $jsonData;
 	}
-}
\ No newline at end of file
+}
diff --git a/src/JsonPrimitive/JsonArrayPrimitive.php b/src/JsonPrimitive/JsonArrayPrimitive.php
index 5259cc0..5742221 100644
--- a/src/JsonPrimitive/JsonArrayPrimitive.php
+++ b/src/JsonPrimitive/JsonArrayPrimitive.php
@@ -2,8 +2,8 @@
 namespace Gt\Json\JsonPrimitive;
 
 class JsonArrayPrimitive extends JsonPrimitive {
-	/** @return mixed[] */
+	/** @return array<mixed> */
 	public function getPrimitiveValue():array {
 		return (array)$this->value;
 	}
-}
\ No newline at end of file
+}
diff --git a/src/JsonPrimitive/JsonNullPrimitive.php b/src/JsonPrimitive/JsonNullPrimitive.php
index 2108444..0d2f244 100644
--- a/src/JsonPrimitive/JsonNullPrimitive.php
+++ b/src/JsonPrimitive/JsonNullPrimitive.php
@@ -2,7 +2,7 @@
 namespace Gt\Json\JsonPrimitive;
 
 class JsonNullPrimitive extends JsonPrimitive {
-	public function getPrimitiveValue() {
+	public function getPrimitiveValue():mixed {
 		return null;
 	}
-}
\ No newline at end of file
+}
diff --git a/src/JsonPrimitive/JsonPrimitive.php b/src/JsonPrimitive/JsonPrimitive.php
index 6a8d749..1b7ec56 100644
--- a/src/JsonPrimitive/JsonPrimitive.php
+++ b/src/JsonPrimitive/JsonPrimitive.php
@@ -4,10 +4,14 @@
 use Gt\Json\JsonObject;
 
 abstract class JsonPrimitive extends JsonObject {
+	/** @var bool|int|float|string|array<mixed>|null */
 	protected bool|int|float|string|array|null $value;
 
-	abstract public function getPrimitiveValue();
+	abstract public function getPrimitiveValue():mixed;
 
+	/**
+	 * @param bool|int|float|string|array<mixed>|null $value
+	 */
 	public function withPrimitiveValue(
 		bool|int|float|string|array|null $value
 	):static {
@@ -15,4 +19,4 @@ public function withPrimitiveValue(
 		$clone->value = $value;
 		return $clone;
 	}
-}
\ No newline at end of file
+}