diff --git a/README.md b/README.md
index 1e07f27..1e33640 100644
--- a/README.md
+++ b/README.md
@@ -86,7 +86,7 @@ An explicitly supplied `--config` path must exist. Config files are validated be
 
 ScriptAudit is a static heuristic tool, not a shell sandbox. It does not prove that a command is safe, and it does not replace maintainer judgment. Treat reports as a review appendix before running commands in an unfamiliar repo.
 
-Discovery is fail-closed for invalid command sources. Malformed `package.json` or Taskfile YAML, non-string `package.json` script values, and unsupported or malformed Taskfile `cmds` entries stop the scan with a nonzero exit and a path-specific diagnostic; they are never treated as a clean zero-command audit.
+Discovery is fail-closed for invalid command sources. Malformed `package.json` or Taskfile YAML, present non-object `scripts` or `tasks` containers, non-object Taskfile task definitions, non-string `package.json` script values, and unsupported or malformed Taskfile `cmds` entries stop the scan with a nonzero exit and a path-specific diagnostic; they are never treated as a clean zero-command audit. An omitted `scripts` or `tasks` field is valid and contributes no commands.
 
 ## Agent Workflow
 
diff --git a/src/discover/package-json.ts b/src/discover/package-json.ts
index 23f19dd..313734f 100644
--- a/src/discover/package-json.ts
+++ b/src/discover/package-json.ts
@@ -13,7 +13,7 @@ export async function discoverPackageScripts(root: string): Promise<CommandSourc
 
   for (const filePath of packageFiles) {
     const manifest = await readJson<PackageJson>(filePath);
-    if (!manifest?.scripts) {
+    if (manifest?.scripts === undefined) {
       continue;
     }
 
diff --git a/src/discover/taskfiles.ts b/src/discover/taskfiles.ts
index 97e8521..9f4dd70 100644
--- a/src/discover/taskfiles.ts
+++ b/src/discover/taskfiles.ts
@@ -54,12 +54,15 @@ function discoverTaskfile(file: string, text: string): CommandSource[] {
   } catch {
     throw new Error(`Invalid Taskfile YAML in ${file}.`);
   }
-  if (!isRecord(document) || !isRecord(document.tasks)) {
+  if (!isRecord(document) || document.tasks === undefined) {
     return commands;
   }
+  if (!isRecord(document.tasks)) {
+    throw new Error(`Invalid Taskfile tasks in ${file}: tasks must be an object.`);
+  }
   for (const [name, task] of Object.entries(document.tasks)) {
     if (!isRecord(task)) {
-      continue;
+      throw new Error(`Invalid Taskfile task in ${file} at tasks.${name}: expected an object.`);
     }
     const body = taskCommands(task.cmds, file, name);
     if (body) {
diff --git a/tests/cli.test.mjs b/tests/cli.test.mjs
index 07cf1b6..3cfa3a5 100644
--- a/tests/cli.test.mjs
+++ b/tests/cli.test.mjs
@@ -97,6 +97,23 @@ test("CLI rejects non-string package scripts with a path-specific diagnostic", (
   assert.equal(result.stderr, "Invalid package script in package.json at scripts.test: expected a string.\n");
 });
 
+test("CLI rejects a null package scripts container instead of reporting zero commands", () => {
+  const root = mkdtempSync(path.join(os.tmpdir(), "scriptaudit-null-scripts-"));
+  writeFileSync(path.join(root, "package.json"), '{"name":"probe","scripts":null}');
+  const result = scan(root);
+  assert.equal(result.status, 1);
+  assert.equal(result.stdout, "");
+  assert.equal(result.stderr, "Invalid package scripts in package.json: scripts must be an object of string values.\n");
+});
+
+test("CLI accepts an absent package scripts container", () => {
+  const root = mkdtempSync(path.join(os.tmpdir(), "scriptaudit-absent-scripts-"));
+  writeFileSync(path.join(root, "package.json"), '{"name":"probe"}');
+  const result = scan(root);
+  assert.equal(result.status, 0, result.stderr);
+  assert.equal(JSON.parse(result.stdout).summary.total, 0);
+});
+
 test("CLI rejects malformed package JSON with the discovered path", () => {
   const root = mkdtempSync(path.join(os.tmpdir(), "scriptaudit-invalid-json-"));
   mkdirSync(path.join(root, "nested"));
@@ -145,6 +162,23 @@ test("CLI rejects malformed Taskfile command entries with a path-specific diagno
   );
 });
 
+test("CLI rejects a non-object Taskfile task instead of reporting zero commands", () => {
+  const root = mkdtempSync(path.join(os.tmpdir(), "scriptaudit-invalid-task-"));
+  writeFileSync(path.join(root, "Taskfile.yml"), "version: '3'\ntasks:\n  broken: npm test\n");
+  const result = scan(root);
+  assert.equal(result.status, 1);
+  assert.equal(result.stdout, "");
+  assert.equal(result.stderr, "Invalid Taskfile task in Taskfile.yml at tasks.broken: expected an object.\n");
+});
+
+test("CLI accepts an absent Taskfile tasks container", () => {
+  const root = mkdtempSync(path.join(os.tmpdir(), "scriptaudit-absent-tasks-"));
+  writeFileSync(path.join(root, "Taskfile.yml"), "version: '3'\n");
+  const result = scan(root);
+  assert.equal(result.status, 0, result.stderr);
+  assert.equal(JSON.parse(result.stdout).summary.total, 0);
+});
+
 function scan(root) {
   return spawnSync(process.execPath, [cli, "scan", root, "--format", "json"], {
     cwd: repo,