diff --git a/bgpwtf/invoice/BUILD.bazel b/bgpwtf/invoice/BUILD.bazel
index 900f0b3..950474e 100644
--- a/bgpwtf/invoice/BUILD.bazel
+++ b/bgpwtf/invoice/BUILD.bazel
@@ -1,4 +1,4 @@
-load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library")
+load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
@@ -31,3 +31,9 @@
     embed = [":go_default_library"],
     visibility = ["//visibility:public"],
 )
+
+go_test(
+    name = "go_default_test",
+    srcs = ["calc_test.go"],
+    embed = [":go_default_library"],
+)