diff --git a/website/docs/r/security_group_rule.html.markdown b/website/docs/r/security_group_rule.html.markdown
index 2439da4deff..4a7faef1621 100644
--- a/website/docs/r/security_group_rule.html.markdown
+++ b/website/docs/r/security_group_rule.html.markdown
@@ -32,7 +32,7 @@ resource "aws_security_group_rule" "example" {
   from_port         = 0
   to_port           = 65535
   protocol          = "tcp"
-  cidr_blocks       = aws_vpc.example.cidr_block
+  cidr_blocks       = [aws_vpc.example.cidr_block]
   security_group_id = "sg-123456"
 }
 ```