diff --git a/src/lower.test.ts b/src/codegen.test.ts
similarity index 94%
rename from src/lower.test.ts
rename to src/codegen.test.ts
index 72841f5..36585a8 100644
--- a/src/lower.test.ts
+++ b/src/codegen.test.ts
@@ -1,5 +1,5 @@
 import { TY_I32, TY_INT, TyStruct } from "./ast";
-import { layoutOfStruct } from "./lower";
+import { layoutOfStruct } from "./codegen";
 
 it("should compute struct layout correctly", () => {
   const ty: TyStruct = {
diff --git a/src/lower.ts b/src/codegen.ts
similarity index 99%
rename from src/lower.ts
rename to src/codegen.ts
index 4f6d0a8..1bc346c 100644
--- a/src/lower.ts
+++ b/src/codegen.ts
@@ -1012,6 +1012,8 @@ function lowerExpr(
       expr.fields.forEach((field) => lowerExpr(fcx, instrs, field));
       break;
     }
+    case "refcount":
+      todo("refcount");
     default: {
       const _: never = expr;
     }