diff --git a/graphql/handler/transport/http_get.go b/graphql/handler/transport/http_get.go
index 35d9a58be4c..d97c89c63fd 100644
--- a/graphql/handler/transport/http_get.go
+++ b/graphql/handler/transport/http_get.go
@@ -27,6 +27,8 @@ func (h GET) Supports(r *http.Request) bool {
 }
 
 func (h GET) Do(w http.ResponseWriter, r *http.Request, exec graphql.GraphExecutor) {
+	w.Header().Set("Content-Type", "application/json")
+
 	raw := &graphql.RawParams{
 		Query:         r.URL.Query().Get("query"),
 		OperationName: r.URL.Query().Get("operationName"),