diff --git a/src/rules/expect-expect.ts b/src/rules/expect-expect.ts
index 2a0c664..3b6190c 100644
--- a/src/rules/expect-expect.ts
+++ b/src/rules/expect-expect.ts
@@ -1,6 +1,6 @@
 import { Rule } from 'eslint';
 import * as ESTree from 'estree';
-import { isExpectCall, isIdentifier, isTest } from '../utils/ast';
+import { dig, isExpectCall, isTest } from '../utils/ast';
 import { getAdditionalAssertFunctionNames } from '../utils/misc';
 
 function isAssertionCall(
@@ -9,9 +9,7 @@ function isAssertionCall(
 ) {
   return (
     isExpectCall(node) ||
-    additionalAssertFunctionNames.find((name) =>
-      isIdentifier(node.callee, name),
-    )
+    additionalAssertFunctionNames.find((name) => dig(node.callee, name))
   );
 }
 
@@ -38,7 +36,7 @@ export default {
         if (isTest(node, ['fixme', 'only', 'skip'])) {
           unchecked.push(node);
         } else if (isAssertionCall(node, additionalAssertFunctionNames)) {
-          checkExpressions(context.getAncestors());
+          checkExpressions(context.sourceCode.getAncestors(node));
         }
       },
       'Program:exit'() {
diff --git a/src/utils/ast.ts b/src/utils/ast.ts
index 828ebc1..516b2ef 100644
--- a/src/utils/ast.ts
+++ b/src/utils/ast.ts
@@ -158,7 +158,7 @@ export function getMatchers(
  * Digs through a series of MemberExpressions and CallExpressions to find an
  * Identifier with the given name.
  */
-function dig(node: ESTree.Node, identifier: string | RegExp): boolean {
+export function dig(node: ESTree.Node, identifier: string | RegExp): boolean {
   return node.type === 'MemberExpression'
     ? dig(node.property, identifier)
     : node.type === 'CallExpression'
diff --git a/test/spec/expect-expect.spec.ts b/test/spec/expect-expect.spec.ts
index f71444e..da88de8 100644
--- a/test/spec/expect-expect.spec.ts
+++ b/test/spec/expect-expect.spec.ts
@@ -93,7 +93,20 @@ runRuleTester('expect-expect', rule, {
           await assertCustomCondition(page)
         })
       `,
-      name: 'Global settings only',
+      name: 'Custom assert function',
+      settings: {
+        playwright: {
+          additionalAssertFunctionNames: ['assertCustomCondition'],
+        },
+      },
+    },
+    {
+      code: dedent`
+        test('should fail', async ({ myPage, page }) => {
+          await myPage.assertCustomCondition(page)
+        })
+      `,
+      name: 'Custom assert class method',
       settings: {
         playwright: {
           additionalAssertFunctionNames: ['assertCustomCondition'],