diff --git a/.spacelift/config.yml b/.spacelift/config.yml
index 8ec282938..279a9441a 100644
--- a/.spacelift/config.yml
+++ b/.spacelift/config.yml
@@ -1,4 +1,4 @@
 version: 1
 
 
-module_version: 0.3.5
+module_version: 0.3.6
diff --git a/tgw.tf b/tgw.tf
index 4c856123a..fa591fc77 100644
--- a/tgw.tf
+++ b/tgw.tf
@@ -157,9 +157,10 @@ resource "aws_network_acl_rule" "tgw_outbound" {
 resource "aws_ec2_transit_gateway_vpc_attachment" "tgw" {
   count = var.enable_tgw_attachment ? 1 : 0
 
-  subnet_ids         = aws_subnet.tgw[*].id
-  transit_gateway_id = var.transit_gateway_id
-  vpc_id             = local.vpc_id
+  subnet_ids             = aws_subnet.tgw[*].id
+  transit_gateway_id     = var.transit_gateway_id
+  vpc_id                 = local.vpc_id
+  appliance_mode_support = try(var.enable_appliance_mode_support, false) ? "enable" : "disable"
 
   tags = merge(
     { Name = "${var.name_prefix}-${var.short_aws_region}-tgw-att-${var.tgw_att_suffix}" }
diff --git a/variables.tf b/variables.tf
index 453578a24..a27646a81 100644
--- a/variables.tf
+++ b/variables.tf
@@ -1796,6 +1796,12 @@ variable "create_multiple_tgw_route_tables" {
   default     = true
 }
 
+variable "enable_appliance_mode_support" {
+  description = "Enable/disable support for appliance mode for the TGW attachment. Default:; `false`"
+  type        = bool
+  default     = false
+}
+
 ################################################################################
 # TGW Network ACLs
 ################################################################################