diff --git a/enervent-ctrl-go/main.go b/enervent-ctrl-go/main.go
index a89df7c..fc63644 100644
--- a/enervent-ctrl-go/main.go
+++ b/enervent-ctrl-go/main.go
@@ -14,6 +14,7 @@ var (
 )
 
 func coils(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(pingvin.Coils)
 }