diff --git a/composer.json b/composer.json
index d14d0e4..e604a2d 100644
--- a/composer.json
+++ b/composer.json
@@ -9,7 +9,7 @@
   },
   "require": {
     "ext-curl": "*",
-    "php": ">=7.3",
+    "php": "^7.3||^8",
     "php-curl-class/php-curl-class": "^8.6"
   },
   "require-dev": {
diff --git a/tests/IpIntel/IpIntelTest.php b/tests/IpIntel/IpIntelTest.php
index 37da101..14c8e69 100644
--- a/tests/IpIntel/IpIntelTest.php
+++ b/tests/IpIntel/IpIntelTest.php
@@ -108,4 +108,28 @@ public function testValidateThrowsExceptionOnServiceError(): void
 
         $this->ipIntel->validate($ip, 0.2);
     }
+
+    public function testValidateThrowsExceptionOnEmptyResponse(): void
+    {
+        $this->expectException(ServiceException::class);
+
+        $ip = '666.42.33.21';
+
+        $this->curl->shouldReceive('setTimeout')
+            ->with(5)
+            ->once();
+
+        $this->curl->shouldReceive('get')
+            ->with(
+                'https://check.getipintel.net/check.php',
+                [
+                    'ip' => $ip,
+                    'contact' => $this->contactEmailAddress
+                ]
+            )
+            ->once()
+            ->andReturnNull();
+
+        $this->ipIntel->validate($ip, 0.2);
+    }
 }