diff --git a/src/bin/bolt-selftest.ts b/src/bin/bolt-selftest.ts
index 9ad56981f..b67482ae1 100644
--- a/src/bin/bolt-selftest.ts
+++ b/src/bin/bolt-selftest.ts
@@ -9,9 +9,7 @@ import path from "path";
 import yargs from "yargs";
 import { Checker } from "../checker";
 import { TextFile } from "../cst";
-import { Parser } from "../parser";
-import { Punctuator, Scanner } from "../scanner";
-import { ConsoleDiagnostics, DiagnosticStore } from "../diagnostics";
+import { ConsoleDiagnostics } from "../diagnostics";
 import { parseSourceFile } from "..";
 
 const projectDir = path.resolve(__dirname, '..', '..');
@@ -40,12 +38,12 @@ yargs
 async function* loadTests(): AsyncIterable<Test> {
   for (const filename of globSync(path.join(projectDir, 'src', 'test', '**', '*.md'))) {
     const text = await fs.promises.readFile(filename, 'utf-8');
-    const reader = commonmark.Parser();
+    const reader = new commonmark.Parser();
     const root = reader.parse(text);
     let child = root.firstChild;
     while (child !== null) {
       if (child.type === 'code_block') {
-        yield { code: child.literal };
+        yield { code: child.literal! };
       }
       child = child.next;
     }