diff --git a/functionMap.php b/functionMap.php
index 9fa6e10..d75377e 100644
--- a/functionMap.php
+++ b/functionMap.php
@@ -52,6 +52,7 @@
     'WP_Http::post' => [$httpReturnType],
     'WP_Http::request' => [$httpReturnType],
     'wp_list_bookmarks' => ['($args is array{echo: false|0} ? string : void)'],
+    'wp_list_categories' => ['($args is array{echo: false|0} ? string|false : false|void)'],
     'wp_list_pages' => ['($args is array{echo: false} ? string : void)'],
     'WP_List_Table::set_pagination_args' => ['void', 'args' => 'array{total_items?: int, total_pages?: int, per_page?: int}'],
     'wp_next_scheduled' => [null, 'args' => $cronArgsType],
diff --git a/tests/TypeInferenceTest.php b/tests/TypeInferenceTest.php
index 34c271f..c254ac0 100644
--- a/tests/TypeInferenceTest.php
+++ b/tests/TypeInferenceTest.php
@@ -36,6 +36,7 @@ public function dataFileAsserts(): iterable
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_error_parameter.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_get_archives.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_list_bookmarks.php');
+        yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_list_categories.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_list_pages.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_rest_request.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_theme.php');
diff --git a/tests/data/wp_list_categories.php b/tests/data/wp_list_categories.php
new file mode 100644
index 0000000..1e88675
--- /dev/null
+++ b/tests/data/wp_list_categories.php
@@ -0,0 +1,31 @@
+<?php
+
+/**
+ * Note:
+ * Starting from PHPStan 1.10.49, void types, including void in unions, are
+ * transformed into null.
+ *
+ * @link https://github.com/phpstan/phpstan-src/pull/2778
+ */
+
+declare(strict_types=1);
+
+namespace PhpStubs\WordPress\Core\Tests;
+
+use function wp_list_categories;
+use function PHPStan\Testing\assertType;
+
+// Default value of 1
+assertType('false|null', wp_list_categories());
+
+// Explicit value of true|1
+assertType('false|null', wp_list_categories(['echo' => true, 'key' => 'value']));
+assertType('false|null', wp_list_categories(['echo' => 1, 'key' => 'value']));
+
+// Explicit value of false|0
+assertType('string|false', wp_list_categories(['echo' => false, 'key' => 'value']));
+assertType('string|false', wp_list_categories(['echo' => 0, 'key' => 'value']));
+
+// Unknown value
+assertType('string|false|null', wp_list_categories(['echo' => (bool)$GET['echo'], 'key' => 'value']));
+assertType('string|false|null', wp_list_categories(['echo' => (int)$GET['echo'], 'key' => 'value']));
diff --git a/wordpress-stubs.php b/wordpress-stubs.php
index e4b594e..0adb11a 100644
--- a/wordpress-stubs.php
+++ b/wordpress-stubs.php
@@ -102127,6 +102127,7 @@ function wp_dropdown_categories($args = '')
      *   walker?: Walker,
      *   taxonomy?: string,
      * } $args
+     * @phpstan-return ($args is array{echo: false|0} ? string|false : false|void)
      */
     function wp_list_categories($args = '')
     {