diff --git a/vpc-interface-endpoint/main.tf b/vpc-interface-endpoint/main.tf
index 6e12cc2..0887e83 100644
--- a/vpc-interface-endpoint/main.tf
+++ b/vpc-interface-endpoint/main.tf
@@ -34,7 +34,7 @@ locals {
   account_environment = data.aws_arn.current.partition == "aws-us-gov" ? "gov" : "ew"
   region              = data.aws_region.current.name
 
-  service       = length(regexall("^com.amazonaws", var.service)) > 0 ? var.service : format("com.amazonaws.%v.%v", local.region, var.service)
+  service       = length(regexall("^com.amazonaws", var.service)) == 0 ? var.service : format("com.amazonaws.%v.%v", local.region, var.service)
   _service      = split(".", local.service)
   short_service = element(local._service, length(local._service))