diff --git a/dev/lib/math-flow.js b/dev/lib/math-flow.js
index 8f0d6a0..d795fab 100644
--- a/dev/lib/math-flow.js
+++ b/dev/lib/math-flow.js
@@ -10,7 +10,8 @@ import {codes, constants, types} from 'micromark-util-symbol'
 /** @type {Construct} */
 export const mathFlow = {
   tokenize: tokenizeMathFenced,
-  concrete: true
+  concrete: true,
+  name: 'mathFlow'
 }
 
 /** @type {Construct} */
diff --git a/dev/lib/math-text.js b/dev/lib/math-text.js
index 89bc08b..808814f 100644
--- a/dev/lib/math-text.js
+++ b/dev/lib/math-text.js
@@ -27,7 +27,8 @@ export function mathText(options) {
   return {
     tokenize: tokenizeMathText,
     resolve: resolveMathText,
-    previous
+    previous,
+    name: 'mathText'
   }
 
   /**
diff --git a/test/index.js b/test/index.js
index 9a5cc7f..edaf338 100644
--- a/test/index.js
+++ b/test/index.js
@@ -14,6 +14,19 @@ test('math', async function (t) {
     )
   })
 
+  await t.test(
+    'should skip `mathFlow` and `mathText` construct  if `disable.null` includes `mathFlow` and `mathText`',
+    async function () {
+      assert.equal(
+        micromark('$a$, $$b$$, $$$c$$$', {
+          extensions: [math(), {disable: {null: ['mathFlow', 'mathText']}}],
+          htmlExtensions: [mathHtml()]
+        }),
+        '<p>$a$, $$b$$, $$$c$$$</p>'
+      )
+    }
+  )
+
   await t.test(
     'should support one, two, or more dollars by default',
     async function () {