diff --git a/app/server.ts b/app/server.ts
index 75207fbb30133c65d35835712d14a6a694e704b0..373942d41fbdd35cbc5484dce0b226b80030459a 100644
--- a/app/server.ts
+++ b/app/server.ts
@@ -180,9 +180,8 @@ export const createGraphQLServer = (config: ServerConfig): GraphQLServer => {
     graphiql: true,
     plugins,
     context: (context: GraphQLContext) => {
-      const languages = (context.params?.extensions?.headers || {})[
-        "accept-language"
-      ];
+      const headers = new Headers(context.params?.extensions?.headers);
+      const languages = headers.get("accept-language") || DEFAULT_LANGUAGE;
       return {
         ...context,
         language: getLanguage(languages),