diff --git a/functionMap.php b/functionMap.php
index 8c8e353..89911d4 100644
--- a/functionMap.php
+++ b/functionMap.php
@@ -46,6 +46,7 @@
     'wp_die' => ['($args is array{exit: false} ? void : never))'],
     'wp_dropdown_languages' => ["(\$args is array{id: null|''} ? void : (\$args is array{name: null|''} ? void : string))"],
     'wp_clear_scheduled_hook' => ['(0|positive-int|($wp_error is false ? false : \WP_Error))', 'args' => $cronArgsType],
+    'wp_generate_tag_cloud' => ["(\$args is array{format: 'array'} ? array<int, string> : string)"],
     'wp_get_schedule' => [null, 'args' => $cronArgsType],
     'wp_get_scheduled_event' => [null, 'args' => $cronArgsType],
     'wp_get_archives' => ['($args is array{echo: false|0} ? string : void)'],
diff --git a/tests/TypeInferenceTest.php b/tests/TypeInferenceTest.php
index abe835d..b04f6db 100644
--- a/tests/TypeInferenceTest.php
+++ b/tests/TypeInferenceTest.php
@@ -38,6 +38,7 @@ public function dataFileAsserts(): iterable
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_die.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_dropdown_languages.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_error_parameter.php');
+        yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_generate_tag_cloud.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_get_archives.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_is_numeric_array.php');
         yield from $this->gatherAssertTypes(__DIR__ . '/data/wp_list_bookmarks.php');
diff --git a/tests/data/wp_generate_tag_cloud.php b/tests/data/wp_generate_tag_cloud.php
new file mode 100644
index 0000000..9f52eff
--- /dev/null
+++ b/tests/data/wp_generate_tag_cloud.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpStubs\WordPress\Core\Tests;
+
+use function wp_generate_tag_cloud;
+use function PHPStan\Testing\assertType;
+
+/** @var array<\WP_Term> $args */
+$tags = $_GET['tags'];
+
+// Default $args['format] value.
+assertType('string', wp_generate_tag_cloud($tags));
+assertType('string', wp_generate_tag_cloud($tags, []));
+
+// Requesting array
+assertType('array<int, string>', wp_generate_tag_cloud($tags, ['format' => 'array', 'key' => 'value']));
+
+// Requesting string
+assertType('string', wp_generate_tag_cloud($tags, ['format' => 'list', 'key' => 'value']));
+assertType('string', wp_generate_tag_cloud($tags, ['format' => 'flat', 'key' => 'value']));
+
+// Unexpected $args['format] value
+assertType('string', wp_generate_tag_cloud($tags, ['format' => 'unexpected', 'key' => 'value']));
+
+// Unknown $args['format] value
+assertType('array<int, string>|string', wp_generate_tag_cloud($tags, ['format' => (string)$_GET['format'], 'key' => 'value']));
diff --git a/wordpress-stubs.php b/wordpress-stubs.php
index 1496324..3b98d37 100644
--- a/wordpress-stubs.php
+++ b/wordpress-stubs.php
@@ -102255,6 +102255,7 @@ function default_topic_count_scale($count)
      *   topic_count_scale_callback?: callable,
      *   show_count?: bool|int,
      * } $args
+     * @phpstan-return ($args is array{format: 'array'} ? array<int, string> : string)
      */
     function wp_generate_tag_cloud($tags, $args = '')
     {