diff --git a/test/unit/_macros.js b/test/unit/_macros.js
index f5bb636da..9baa2b86c 100644
--- a/test/unit/_macros.js
+++ b/test/unit/_macros.js
@@ -3,7 +3,10 @@
  * @license MIT
  */
 
+import { performance } from "node:perf_hooks";
+
 import test from "ava";
+import fc from "fast-check";
 
 /**
  * Transforms a string by replacing control characters with unicode point codes
@@ -94,6 +97,36 @@ export const flag = test.macro({
   },
 });
 
+/**
+ * The flag macro tests the behaviour of the function returned by the provided
+ * `getFlagProtectionFunction`.
+ *
+ * @param {object} t The AVA test object.
+ * @param {object} args The arguments for this function.
+ * @param {any} args.arbitraries The arbitraries to test with.
+ * @param {number} args.maxMillis The maximum duration in milliseconds.
+ * @param {Function} args.setup A function to setup the function to test.
+ */
+export const duration = test.macro({
+  exec(t, { arbitraries, maxMillis, setup }) {
+    fc.assert(
+      fc.property(...arbitraries, (...args) => {
+        const fn = setup();
+
+        const startTime = performance.now();
+        try {
+          fn(...args);
+        } catch (_) {
+          // not concerned about functional correctness
+        }
+        const endTime = performance.now();
+
+        t.true(endTime - startTime < maxMillis);
+      }),
+    );
+  },
+});
+
 /**
  * The quote macro tests the behaviour of the function returned by the provided
  * `getQuoteFunction`.
diff --git a/test/unit/unix/shells.test.js b/test/unit/unix/shells.test.js
index 3487b7423..d87fc1313 100644
--- a/test/unit/unix/shells.test.js
+++ b/test/unit/unix/shells.test.js
@@ -44,6 +44,20 @@ for (const [shellName, shellExports] of Object.entries(shells)) {
     t.is(typeof result, "string");
   });
 
+  test(`escape performance for ${shellName}`, macros.duration, {
+    arbitraries: [fc.string({ size: "xlarge" })],
+    maxMillis: 50,
+    setup: shellExports.getEscapeFunction,
+  });
+
+  redosFixtures.forEach((input, id) => {
+    test(`${shellName}, ReDoS #${id}`, (t) => {
+      const escape = shellExports.getEscapeFunction();
+      escape(input);
+      t.pass();
+    });
+  });
+
   flagFixtures.forEach(({ input, expected }) => {
     test(macros.flag, {
       expected: expected.unquoted,
@@ -63,6 +77,12 @@ for (const [shellName, shellExports] of Object.entries(shells)) {
     },
   );
 
+  test(`flag protection performance for ${shellName}`, macros.duration, {
+    arbitraries: [fc.string({ size: "xlarge" })],
+    maxMillis: 50,
+    setup: shellExports.getFlagProtectionFunction,
+  });
+
   if (shellExports !== nosh) {
     quoteFixtures.forEach(({ input, expected }) => {
       test(macros.quote, {
@@ -80,13 +100,14 @@ for (const [shellName, shellExports] of Object.entries(shells)) {
       const result = quoteFn(intermediate);
       t.is(typeof result, "string");
     });
-  }
 
-  redosFixtures.forEach((input, id) => {
-    test(`${shellName}, ReDoS #${id}`, (t) => {
-      const escape = shellExports.getEscapeFunction();
-      escape(input);
-      t.pass();
+    test(`quote performance for ${shellName}`, macros.duration, {
+      arbitraries: [fc.string({ size: "xlarge" })],
+      maxMillis: 50,
+      setup: () => {
+        const [escapeFn, quoteFn] = shellExports.getQuoteFunction();
+        return (arg) => quoteFn(escapeFn(arg));
+      },
     });
-  });
+  }
 }
diff --git a/test/unit/win/shells.test.js b/test/unit/win/shells.test.js
index 101db9e87..e004b2370 100644
--- a/test/unit/win/shells.test.js
+++ b/test/unit/win/shells.test.js
@@ -39,6 +39,12 @@ for (const [shellName, shellExports] of Object.entries(shells)) {
     t.is(typeof result, "string");
   });
 
+  test(`escape performance for ${shellName}`, macros.duration, {
+    arbitraries: [fc.string({ size: "xlarge" })],
+    maxMillis: 50,
+    setup: shellExports.getEscapeFunction,
+  });
+
   flagFixtures.forEach(({ input, expected }) => {
     test(macros.flag, {
       expected: expected.unquoted,
@@ -58,6 +64,12 @@ for (const [shellName, shellExports] of Object.entries(shells)) {
     },
   );
 
+  test(`flag protection performance for ${shellName}`, macros.duration, {
+    arbitraries: [fc.string({ size: "xlarge" })],
+    maxMillis: 50,
+    setup: shellExports.getFlagProtectionFunction,
+  });
+
   if (shellExports !== nosh) {
     quoteFixtures.forEach(({ input, expected }) => {
       test(macros.quote, {
@@ -75,5 +87,14 @@ for (const [shellName, shellExports] of Object.entries(shells)) {
       const result = quoteFn(intermediate);
       t.is(typeof result, "string");
     });
+
+    test(`quote performance for ${shellName}`, macros.duration, {
+      arbitraries: [fc.string({ size: "xlarge" })],
+      maxMillis: 50,
+      setup: () => {
+        const [escapeFn, quoteFn] = shellExports.getQuoteFunction();
+        return (arg) => quoteFn(escapeFn(arg));
+      },
+    });
   }
 }