diff --git a/env_test.go b/env_test.go
new file mode 100644
index 0000000..cb3c2b1
--- /dev/null
+++ b/env_test.go
@@ -0,0 +1,12 @@
+package main
+
+import (
+	"os"
+	"testing"
+)
+
+func TestDogfoodEnv(t *testing.T) {
+	if got := os.Getenv("DOGFOOD_35"); got != "1" {
+		t.Fatalf("expected DOGFOOD_35=1, got %q", got)
+	}
+}