diff --git a/4dev/tests/UrlRequests/CoreLibsUrlRequestsCurlTest.php b/4dev/tests/UrlRequests/CoreLibsUrlRequestsCurlTest.php
index 9e4432e4..3d751c6f 100644
--- a/4dev/tests/UrlRequests/CoreLibsUrlRequestsCurlTest.php
+++ b/4dev/tests/UrlRequests/CoreLibsUrlRequestsCurlTest.php
@@ -1043,6 +1043,46 @@ final class CoreLibsUrlRequestsCurlTest extends TestCase
 		$curl->request('wrong', 'http://foo.bar.com');
 	}
 
+	/**
+	 * Exception:InvalidHeaderKey
+	 *
+	 * @covers ::request
+	 * @testdox UrlRequests\Curl Exception:InvalidHeaderKey
+	 *
+	 * @return void
+	 */
+	public function testExceptionInvalidHeaderKey(): void
+	{
+		$curl = new \CoreLibs\UrlRequests\Curl();
+		$this->expectException(\RuntimeException::class);
+		$this->expectExceptionMessageMatches("/InvalidHeaderKey/");
+		$curl->request('get', $this->url_basic, [
+			"headers" => [
+				"(invalid-key)" => "key"
+			]
+		]);
+	}
+
+	/**
+	 * Exception:InvalidHeaderValue
+	 *
+	 * @covers ::request
+	 * @testdox UrlRequests\Curl Exception:InvalidHeaderValue
+	 *
+	 * @return void
+	 */
+	public function testExceptionInvalidHeaderValue(): void
+	{
+		$curl = new \CoreLibs\UrlRequests\Curl();
+		$this->expectException(\RuntimeException::class);
+		$this->expectExceptionMessageMatches("/InvalidHeaderValue/");
+		$curl->request('get', $this->url_basic, [
+			"headers" => [
+				"invalid-value" => "\x19\x10"
+			]
+		]);
+	}
+
 	/**
 	 * TODO: Exception:CurlInitError
 	 *