diff --git a/src/Api/Client.php b/src/Api/Client.php
index 2fe1571..85276bc 100644
--- a/src/Api/Client.php
+++ b/src/Api/Client.php
@@ -79,9 +79,25 @@ public function requestRaw(Request $request): \stdClass
         return $this->request($request);
     }
 
+    /**
+     * Drupal.org answers unknown node IDs with HTTP 200 and a stub body, and
+     * serves every node type from the same endpoint, so both cases are checked
+     * here rather than surfacing as empty issue fields downstream.
+     *
+     * @throws \RuntimeException
+     *   When the node does not exist or is not an issue.
+     */
     public function getNode(string $nid): IssueNode
     {
-        return IssueNode::fromStdClass($this->request(new Request('node/' . $nid)));
+        $data = $this->request(new Request('node/' . $nid));
+        $type = $data->type ?? null;
+        if (!is_string($type)) {
+            throw new \RuntimeException(sprintf('Node %s was not found on Drupal.org.', $nid));
+        }
+        if ($type !== 'project_issue') {
+            throw new \RuntimeException(sprintf('Node %s is a %s, not an issue.', $nid, $type));
+        }
+        return IssueNode::fromStdClass($data);
     }
 
     public function getFile(string $fid): File
diff --git a/tests/src/ClientTest.php b/tests/src/ClientTest.php
new file mode 100644
index 0000000..e1acecb
--- /dev/null
+++ b/tests/src/ClientTest.php
@@ -0,0 +1,68 @@
+<?php
+
+namespace mglaman\DrupalOrg\Tests;
+
+use GuzzleHttp\Handler\MockHandler;
+use GuzzleHttp\HandlerStack;
+use GuzzleHttp\Psr7\Response;
+use mglaman\DrupalOrg\Client;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\TestCase;
+
+#[CoversClass(Client::class)]
+class ClientTest extends TestCase
+{
+    /**
+     * @param array<string, mixed> $body
+     */
+    private static function clientResponding(array $body): Client
+    {
+        $handler = HandlerStack::create(new MockHandler([
+            new Response(200, ['Content-Type' => 'application/json'], json_encode($body, JSON_THROW_ON_ERROR)),
+        ]));
+        return new class ($handler) extends Client {
+            public function __construct(HandlerStack $handler)
+            {
+                parent::__construct();
+                $this->client = new \GuzzleHttp\Client(['handler' => $handler]);
+            }
+        };
+    }
+
+    public function testGetNodeReturnsIssue(): void
+    {
+        $client = self::clientResponding([
+            'nid' => '3383637',
+            'type' => 'project_issue',
+            'title' => 'Fix the thing',
+            'field_project' => ['id' => '3060', 'machine_name' => 'drupal'],
+        ]);
+
+        $issue = $client->getNode('3383637');
+
+        self::assertSame('3383637', $issue->nid);
+        self::assertSame('drupal', $issue->fieldProjectMachineName);
+    }
+
+    public function testGetNodeRejectsNonIssueNode(): void
+    {
+        $client = self::clientResponding([
+            'nid' => '3000001',
+            'type' => 'project_release',
+            'title' => 'queue_throttle 8.x-1.x-dev',
+        ]);
+
+        $this->expectException(\RuntimeException::class);
+        $this->expectExceptionMessage('Node 3000001 is a project_release, not an issue.');
+        $client->getNode('3000001');
+    }
+
+    public function testGetNodeRejectsMissingNode(): void
+    {
+        $client = self::clientResponding(['comments' => [], 'body' => []]);
+
+        $this->expectException(\RuntimeException::class);
+        $this->expectExceptionMessage('Node 999999999 was not found on Drupal.org.');
+        $client->getNode('999999999');
+    }
+}