diff --git a/tf/alb.tf b/tf/alb.tf
index 0d125bc..d674f8b 100644
--- a/tf/alb.tf
+++ b/tf/alb.tf
@@ -71,6 +71,6 @@ resource "aws_lb_listener" "server_https" {
 resource "aws_autoscaling_attachment" "server" {
   count = local.ami_available ? 1 : 0
 
-  autoscaling_group_name = aws_autoscaling_group.server[0].name
+  autoscaling_group_name = aws_autoscaling_group.server[count.index].name
   alb_target_group_arn = aws_lb_target_group.server.arn
 }
diff --git a/tf/asg.tf b/tf/asg.tf
index c245a7b..42e2557 100644
--- a/tf/asg.tf
+++ b/tf/asg.tf
@@ -38,7 +38,7 @@ resource "aws_launch_template" "server" {
   count = local.ami_available ? 1 : 0
 
   name = "riju-server"
-  image_id = data.aws_ami.server[0].id
+  image_id = data.aws_ami.server[count.index].id
   instance_type = "t3.small"
 
   security_group_names = [aws_security_group.server.name]
@@ -81,7 +81,7 @@ resource "aws_autoscaling_group" "server" {
   max_size = 3
 
   launch_template {
-    id = aws_launch_template.server[0].id
+    id = aws_launch_template.server[count.index].id
   }
 
   tags = concat(
diff --git a/tf/backup.tf b/tf/backup.tf
index 10949b7..ed5e214 100644
--- a/tf/backup.tf
+++ b/tf/backup.tf
@@ -28,6 +28,6 @@ resource "aws_backup_selection" "riju" {
   plan_id = aws_backup_plan.riju.id
 
   resources = [
-    aws_instance.dev_server[0].arn,
+    aws_instance.dev_server[count.index].arn,
   ]
 }
diff --git a/tf/ec2.tf b/tf/ec2.tf
index f6db8f4..9609330 100644
--- a/tf/ec2.tf
+++ b/tf/ec2.tf
@@ -31,11 +31,11 @@ resource "aws_security_group" "dev_server" {
 resource "aws_instance" "dev_server" {
   count = local.ssh_key_available ? 1 : 0
 
-  ami = data.aws_ami.ubuntu[0].id
+  ami = data.aws_ami.ubuntu[count.index].id
   instance_type = "t3.2xlarge"
   ebs_optimized = true
 
-  security_groups = [aws_security_group.dev_server[0].name]
+  security_groups = [aws_security_group.dev_server[count.index].name]
 
   iam_instance_profile = aws_iam_instance_profile.dev_server.name
   key_name = data.external.env.result.SSH_KEY_NAME
@@ -69,6 +69,6 @@ resource "aws_eip" "dev_server" {
 
 resource "aws_eip_association" "dev_server" {
   count = local.ssh_key_available ? 1 : 0
-  instance_id = aws_instance.dev_server[0].id
-  allocation_id = aws_eip.dev_server[0].id
+  instance_id = aws_instance.dev_server[count.index].id
+  allocation_id = aws_eip.dev_server[count.index].id
 }