diff --git a/packages/boringlang/src/types/context.ts b/packages/boringlang/src/types/context.ts
index 0fb2717..49817fa 100644
--- a/packages/boringlang/src/types/context.ts
+++ b/packages/boringlang/src/types/context.ts
@@ -24,7 +24,7 @@ export interface Context {
   environment: Record<string, NamedEntity>;
 }
 
-export function getAttr(ctx: Context, name: string, field: string) {
+export function getAttr(ctx: Context, name: string, field: string): TypeUsage {
   const struct = ctx.environment[name];
   if (!struct || struct.namedEntity !== "NamedType") {
     throw Error(`Unknown type ${name}`);