diff --git a/main.tf b/main.tf
index 482cb21..e44d5bf 100644
--- a/main.tf
+++ b/main.tf
@@ -23,7 +23,7 @@ resource "aws_security_group" "main" {
     from_port   = 0
     to_port     = 0
     protocol    = "-1"
-    cidr_blocks = ["${data.aws_vpc.main.cidr_block}"]
+    cidr_blocks = data.aws_vpc.main.cidr_block_associations[*].cidr_block
   }
 
   egress {