diff --git a/handler_utils/debug.go b/handler_utils/debug.go
index ba930cb17f8157ca7d62c2f5c8d0d547103fd8ed..86aa9a5bcad7266c0b8c2e22b9b6ff49b8b4c432 100644
--- a/handler_utils/debug.go
+++ b/handler_utils/debug.go
@@ -72,6 +72,8 @@ func ServeHTTPFunctions(ctx context.Context, lambdaHandler lambda.Handler, w htt
 		w.Header().Set(key, value.(string))
 	}
 
+	w.Header().Set("Content-Type", "application/json")
+
 	w.WriteHeader(int(response["statusCode"].(float64)))
 	_, _ = io.WriteString(w, response["body"].(string))
 }