diff --git a/src/test/java/codes/thischwa/cf/CfClientTest.java b/src/test/java/codes/thischwa/cf/CfClientTest.java
index a5a58d8..5dee4ce 100644
--- a/src/test/java/codes/thischwa/cf/CfClientTest.java
+++ b/src/test/java/codes/thischwa/cf/CfClientTest.java
@@ -35,6 +35,12 @@ public class CfClientTest {
     assumeTrue(API_KEY != null && !API_KEY.isBlank(), "API_KEY not set; skipping pen tests");
   }
 
+  @Test
+  void testUnknownSld() throws Exception {
+    ZoneEntity zone = client.zoneInfo(ZONE_STR);
+    assertThrows(CloudflareNotFoundException.class, () -> client.sldInfo(zone, "unknown", RecordType.A));
+  }
+
   @Test
   void testAddHost() throws Exception {
     ZoneEntity zone = client.zoneInfo(ZONE_STR);