diff --git a/spec/index.html b/spec/index.html
index 6125735e..e3bf0e95 100644
--- a/spec/index.html
+++ b/spec/index.html
@@ -55,6 +55,7 @@ <h1>Options</h1>
       <tr><td>`--assets-dir`</td><td>`assetsDir`</td><td>Directory in which to place assets when using `--assets=external`. Defaults to "assets".</td></tr>
       <tr><td>`--lint-spec`</td><td>`lintSpec`</td><td>Enforce some style and correctness checks.</td></tr>
       <tr><td>`--error-formatter`</td><td></td><td>The <a href="https://eslint.org/docs/user-guide/formatters/">eslint formatter</a> to be used for printing warnings and errors when using `--verbose`. Either the name of a built-in eslint formatter or the package name of an installed eslint compatible formatter.</td></tr>
+      <tr><td>`--max-clause-depth N`</td><td></td><td>Warn when clauses exceed a nesting depth of N.</td></tr>
       <tr><td>`--strict`</td><td></td><td>Exit with an error if there are warnings. Cannot be used with `--watch`.</td></tr>
       <tr><td>`--multipage`</td><td></td><td>Emit a distinct page for each top-level clause.</td></tr>
     </table>
diff --git a/src/args.ts b/src/args.ts
index f7aa0277..9c4453cc 100644
--- a/src/args.ts
+++ b/src/args.ts
@@ -67,6 +67,12 @@ export const options = [
     description:
       'The formatter for warnings and errors; either a path prefixed with "." or "./", or package name, of an installed eslint compatible formatter (default: eslint-formatter-codeframe)',
   },
+  {
+    name: 'max-clause-depth',
+    type: Number,
+    description:
+      'The maximum nesting depth for clauses; exceeding this will cause a warning. Defaults to no limit.',
+  },
   {
     name: 'multipage',
     type: Boolean,
diff --git a/src/clauseNums.ts b/src/clauseNums.ts
index f77f1631..aec3334d 100644
--- a/src/clauseNums.ts
+++ b/src/clauseNums.ts
@@ -9,6 +9,7 @@ export default function iterator(spec: Spec): ClauseNumberIterator {
   const ids: (string | number[])[] = [];
   let inAnnex = false;
   let currentLevel = 0;
+  let hasWarnedForExcessNesting = false;
 
   return {
     next(clauseStack: Clause[], node: HTMLElement) {
@@ -26,10 +27,19 @@ export default function iterator(spec: Spec): ClauseNumberIterator {
         spec.warn({
           type: 'node',
           node,
-          ruleId: 'skipped-caluse',
+          ruleId: 'skipped-clause',
           message: 'clause is being numbered without numbering its parent clause',
         });
       }
+      if (!hasWarnedForExcessNesting && level + 1 > (spec.opts.maxClauseDepth ?? Infinity)) {
+        spec.warn({
+          type: 'node',
+          node,
+          ruleId: 'max-clause-depth',
+          message: `clause exceeds maximum nesting depth of ${spec.opts.maxClauseDepth}`,
+        });
+        hasWarnedForExcessNesting = true;
+      }
 
       const nextNum = annex ? nextAnnexNum : nextClauseNum;
 
diff --git a/src/cli.ts b/src/cli.ts
index cf96ee93..fd038dbc 100644
--- a/src/cli.ts
+++ b/src/cli.ts
@@ -113,6 +113,9 @@ const build = debounce(async function build() {
     if (args['mark-effects']) {
       opts.markEffects = true;
     }
+    if (args['max-clause-depth']) {
+      opts.maxClauseDepth = args['max-clause-depth'];
+    }
     if (args['no-toc'] != null) {
       opts.toc = !args['no-toc'];
     }
diff --git a/src/ecmarkup.ts b/src/ecmarkup.ts
index 34aae168..815b37e8 100644
--- a/src/ecmarkup.ts
+++ b/src/ecmarkup.ts
@@ -32,6 +32,7 @@ export interface Options {
   copyright?: boolean;
   date?: Date;
   location?: string;
+  maxClauseDepth?: number;
   multipage?: boolean;
   extraBiblios?: ExportedBiblio[];
   contributors?: string;
diff --git a/test/errors.js b/test/errors.js
index a99bfb5c..a4fc5275 100644
--- a/test/errors.js
+++ b/test/errors.js
@@ -1237,4 +1237,49 @@ ${M}      </pre>
       `);
     });
   });
+
+  describe('max clause depth', () => {
+    it('max depth', async () => {
+      await assertError(
+        positioned`
+          <emu-clause id="one">
+            <h1>One</h1>
+            ${M}<emu-clause id="two">
+              <h1>Two</h1>
+            </emu-clause>
+            <emu-clause id="two-again">
+              <h1>Not warned</h1>
+            </emu-clause>
+          </emu-clause>
+        `,
+        {
+          ruleId: 'max-clause-depth',
+          nodeType: 'emu-clause',
+          message: 'clause exceeds maximum nesting depth of 1',
+        },
+        {
+          maxClauseDepth: 1,
+        },
+      );
+    });
+
+    it('negative', async () => {
+      await assertErrorFree(
+        `
+          <emu-clause id="one">
+            <h1>One</h1>
+            <emu-clause id="two">
+              <h1>Two</h1>
+            </emu-clause>
+            <emu-clause id="two-again">
+              <h1>Not warned</h1>
+            </emu-clause>
+          </emu-clause>
+        `,
+        {
+          maxClauseDepth: 2,
+        },
+      );
+    });
+  });
 });