diff --git a/ois-scanner/main.tf b/ois-scanner/main.tf
index 83ed4e9..ee5c187 100644
--- a/ois-scanner/main.tf
+++ b/ois-scanner/main.tf
@@ -34,11 +34,11 @@ module "ois-scanner" {
   ingress_cidr_blocks = [
     "148.129.121.0/24",
     "148.129.21.0/24",
-    "172.18.33.207",
-    "172.18.33.208",
-    "172.18.33.210",
-    "172.18.33.211",
-    "172.18.33.213",
+    "172.18.33.207/32",
+    "172.18.33.208/32",
+    "172.18.33.210/32",
+    "172.18.33.211/32",
+    "172.18.33.213/32",
   ]
   ingress_rules = [ "all-all" ]