diff --git a/src/cli.test.ts b/src/cli.test.ts
index beac1e9..6ee0cee 100644
--- a/src/cli.test.ts
+++ b/src/cli.test.ts
@@ -1,6 +1,8 @@
 import { describe, it, expect } from 'vitest';
 import { execSync, spawnSync } from 'node:child_process';
-import { readFileSync, rmSync, writeFileSync } from 'node:fs';
+import { mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
 
 describe('CLI integration', () => {
   const cli = 'npx tsx src/cli.ts';
@@ -36,6 +38,24 @@ describe('CLI integration', () => {
     });
   });
 
+  it('keeps JSON output parseable when saving a baseline', () => {
+    const directory = mkdtempSync(join(tmpdir(), 'typegap-baseline-'));
+    const baseline = join(directory, 'coverage.json');
+    try {
+      const result = spawnSync('npx', [
+        'tsx', 'src/cli.ts', 'fixtures/any-usage', '--format', 'json', '--baseline', baseline,
+      ], { encoding: 'utf8' });
+
+      expect(result.status).toBe(0);
+      const report = JSON.parse(result.stdout) as { total: number; coverage: number };
+      const saved = JSON.parse(readFileSync(baseline, 'utf8')) as { total: number; coverage: number };
+      expect(saved).toMatchObject({ total: report.total, coverage: report.coverage });
+      expect(result.stderr).toContain(`Baseline saved to ${baseline}`);
+    } finally {
+      rmSync(directory, { recursive: true, force: true });
+    }
+  });
+
   it('shows detail mode', () => {
     const output = execSync(`${cli} fixtures/mixed --detail`, { encoding: 'utf-8' });
     expect(output).toContain('Details');
diff --git a/src/cli.ts b/src/cli.ts
index 92eba33..1948be8 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -87,7 +87,9 @@ program
 
     if (opts.baseline) {
       saveBaseline(result, resolve(opts.baseline as string), process.cwd());
-      console.log(`Baseline saved to ${opts.baseline}`);
+      const confirmation = `Baseline saved to ${opts.baseline}`;
+      if (format === 'json') console.error(confirmation);
+      else console.log(confirmation);
     }
 
     process.exit(exitCode);
diff --git a/src/parser.test.ts b/src/parser.test.ts
index f70a471..55e82dd 100644
--- a/src/parser.test.ts
+++ b/src/parser.test.ts
@@ -138,6 +138,16 @@ describe('classifyTypeAnnotation for TSInferType', () => {
 });
 
 describe('classifyTypeAnnotation for nested weak types', () => {
+  it.each([
+    ['keyof any', AnnotationStatus.any],
+    ['keyof unknown', AnnotationStatus.unknown],
+    ['readonly any[]', AnnotationStatus.any],
+    ['readonly unknown[]', AnnotationStatus.unknown],
+  ])('classifies a type-operator wrapped %s', (annotation, expected) => {
+    const nodes = parseSource(`const value: ${annotation} = null as never;`);
+    expect(nodes.find(node => node.kind === 'var')?.status).toBe(expected);
+  });
+
   it.each([
     ['property', '{ value: any }', AnnotationStatus.any],
     ['unknown property', '{ value: unknown }', AnnotationStatus.unknown],
diff --git a/src/parser.ts b/src/parser.ts
index a0df840..9935ebd 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -426,13 +426,21 @@ export function classifyTypeAnnotation(typeNode: TSESTree.TypeNode): AnnotationS
     return classifyTypeAnnotation(rt.typeAnnotation);
   }
 
+  // TSTypeOperator
+  if (typeNode.type === 'TSTypeOperator') {
+    const operator = typeNode as TSESTree.TSTypeOperator;
+    return operator.typeAnnotation
+      ? classifyTypeAnnotation(operator.typeAnnotation)
+      : AnnotationStatus.explicit;
+  }
+
   // TSNamedTupleMember
   if (typeNode.type === 'TSNamedTupleMember') {
     const ntm = typeNode as TSESTree.TSNamedTupleMember;
     return classifyTypeAnnotation(ntm.elementType);
   }
 
-  // TSTypeOperator, TSInferType, TSIndexedAccessType handled above
+  // TSInferType and TSIndexedAccessType are handled above
   // Everything else is explicit
   return AnnotationStatus.explicit;
 }