1 files changed, 9 insertions, 1 deletions

diff --git a/os.ts b/os.ts
index 409c1186f..de4bdf436 100644
--- a/os.ts
+++ b/os.ts
@@ -1,5 +1,7 @@
 import { ModuleInfo } from "./types";
 import { sendMsg } from "./dispatch";
+import { main as pb } from "./msg.pb";
+import { assert } from "./util";
 
 export function exit(code = 0): void {
   sendMsg("os", { exit: { code } });
@@ -12,7 +14,13 @@ export function sourceCodeFetch(
   const res = sendMsg("os", {
     sourceCodeFetch: { moduleSpecifier, containingFile }
   });
-  return res.sourceCodeFetchRes;
+  assert(res.command === pb.Msg.Command.SOURCE_CODE_FETCH_RES);
+  return {
+    moduleName: res.sourceCodeFetchResModuleName,
+    filename: res.sourceCodeFetchResFilename,
+    sourceCode: res.sourceCodeFetchResSourceCode,
+    outputCode: res.sourceCodeFetchResOutputCode
+  };
 }
 
 export function sourceCodeCache(