diff --git a/README.md b/README.md
index e3ee9e3..6d5da0d 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@ A JSON HTTP client library. This project also is the reference implementation fo
 ```{json}
 {
    	"require": {
-        "chroma-x/json-http-client": "~3.0"
+        "chroma-x/json-http-client": "~4.0"
     }
 }
 ```
diff --git a/src/Request/Message/Body/JsonBody.php b/src/Request/Message/Body/JsonBody.php
index bc909e9..bec15e0 100644
--- a/src/Request/Message/Body/JsonBody.php
+++ b/src/Request/Message/Body/JsonBody.php
@@ -22,8 +22,12 @@ public function __construct(array $bodyData)
 		$this->bodyData = $bodyData;
 	}
 
-	public function configureCurl(\CurlHandle $curl): self
+	public function configureCurl(\CurlHandle|false $curl): self
 	{
+		if ($curl === false) {
+			throw new \TypeError('cURL is not a valid CurlHandle class.');
+		}
+
 		$jsonBody = json_encode($this->bodyData);
 		if ($jsonBody === false) {
 			throw new HttpRequestMessageException('JSON body data not serializable.');