diff --git a/website/docs/r/application_gateway.html.markdown b/website/docs/r/application_gateway.html.markdown
index f6e0d992572e8..7d65240bd39eb 100644
--- a/website/docs/r/application_gateway.html.markdown
+++ b/website/docs/r/application_gateway.html.markdown
@@ -29,14 +29,14 @@ resource "azurerm_subnet" "frontend" {
   name                 = "frontend"
   resource_group_name  = azurerm_resource_group.example.name
   virtual_network_name = azurerm_virtual_network.example.name
-  address_prefix       = "10.254.0.0/24"
+  address_prefixes     = ["10.254.0.0/24"]
 }
 
 resource "azurerm_subnet" "backend" {
   name                 = "backend"
   resource_group_name  = azurerm_resource_group.example.name
   virtual_network_name = azurerm_virtual_network.example.name
-  address_prefix       = "10.254.2.0/24"
+  address_prefixes     = ["10.254.2.0/24"]
 }
 
 resource "azurerm_public_ip" "example" {