diff --git a/terraform/nix-build/main.tf b/terraform/nix-build/main.tf
index daf10c3..de73e5e 100644
--- a/terraform/nix-build/main.tf
+++ b/terraform/nix-build/main.tf
@@ -1,5 +1,7 @@
 locals {
-nix_options = "{\"options\": {${join(", ", [for k, v in var.nix_options :  "\"${k}\": \"${v}\""])} } }"
+  nix_options = jsonencode({
+    options = { for k, v in var.nix_options : k => v }
+  })
 }
 data "external" "nix-build" {
   program = [ "${path.module}/nix-build.sh" ]