diff --git a/ip/ip-tests.ts b/ip/ip-tests.ts
index 338c2bc040..3210871ee0 100644
--- a/ip/ip-tests.ts
+++ b/ip/ip-tests.ts
@@ -19,3 +19,4 @@ var buff:any = ip.toBuffer(myIP);
 ip.toString(buff);
 ip.subnet('192.168.1.134', '255.255.255.192');
 ip.cidrSubnet('192.168.1.134/26');
+ip.cidrSubnet('192.168.1.134/26').contains('192.168.1.134');