diff --git a/tests/phpunit/test-wp-user-query.php b/tests/phpunit/test-wp-user-query.php
new file mode 100644
index 0000000..0f4530e
--- /dev/null
+++ b/tests/phpunit/test-wp-user-query.php
@@ -0,0 +1,142 @@
+<?php
+/**
+ * WP_Query tests.
+ *
+ * @package authorship
+ */
+
+declare( strict_types=1 );
+
+namespace Authorship\Tests;
+
+use const Authorship\GUEST_ROLE;
+use const Authorship\POSTS_PARAM;
+
+use WP_User_Query;
+
+class TestWPUserQuery extends TestCase {
+	public function testQueryForAuthorWithPublishedPostsReturnsAttributedAuthors() : void {
+		$factory = self::factory()->post;
+
+		// Attributed to Editor, owned by Admin.
+		$factory->create_and_get( [
+			'post_author' => self::$users['admin']->ID,
+			'post_status' => 'publish',
+			POSTS_PARAM   => [
+				self::$users['editor']->ID,
+			],
+		] );
+
+		// Attributed to Editor, owned by nobody.
+		$factory->create_and_get( [
+			'post_status' => 'publish',
+			POSTS_PARAM   => [
+				self::$users['editor']->ID,
+			],
+		] );
+
+		// Attributed to Guest, owned by Author.
+		$factory->create_and_get( [
+			'post_author' => self::$users['author']->ID,
+			'post_status' => 'publish',
+			POSTS_PARAM   => [
+				self::$users[ GUEST_ROLE ]->ID,
+			],
+		] );
+
+		// Attributed to Guest, owned by Admin.
+		$factory->create_and_get( [
+			'post_author' => self::$users['admin']->ID,
+			'post_status' => 'publish',
+			POSTS_PARAM   => [
+				self::$users[ GUEST_ROLE ]->ID,
+			],
+		] );
+
+		// Owned by Author.
+		$factory->create_and_get( [
+			'post_author' => self::$users['author']->ID,
+			'post_status' => 'publish',
+			'post_type'   => 'non_existent_type',
+		] );
+
+		// Owned by Admin.
+		$factory->create_and_get( [
+			'post_author' => self::$users['admin']->ID,
+			'post_status' => 'publish',
+			'post_type'   => 'non_existent_type',
+		] );
+
+		$common_args = [
+			'fields'  => 'ids',
+			'orderby' => 'ID',
+			'order'   => 'ASC',
+		];
+
+		// Queries for attributed published post types.
+		$test_args = [
+			'has_published_posts' => [ 'post' ],
+		];
+
+		foreach ( $test_args as $test_key => $test_value ) {
+			$args = array_merge( $common_args, [
+				$test_key => $test_value,
+			] );
+
+			$query = new WP_User_Query();
+			$users = $query->query( $args );
+
+			$this->assertSame(
+				[ self::$users['editor']->ID, self::$users[ GUEST_ROLE ]->ID ],
+				$users,
+				"User IDs for attributed {$test_key} query are incorrect."
+			);
+		}
+
+		// Queries for non attributed published post types.
+		$test_args = [
+			'has_published_posts' => [ 'non_existent_type' ],
+		];
+
+		foreach ( $test_args as $test_key => $test_value ) {
+			$args = array_merge( $common_args, [
+				$test_key => $test_value,
+			] );
+
+			$query = new WP_User_Query();
+			$users = $query->query( $args );
+
+			$this->assertSame(
+				[ self::$users['admin']->ID, self::$users['author']->ID ],
+				$users,
+				"User IDs for non attributed {$test_key} query are incorrect."
+			);
+		}
+
+		// Queries for non attributed published post types.
+		$test_args = [
+			'has_published_posts' => [ 'post', 'non_existent_type' ],
+		];
+
+		foreach ( $test_args as $test_key => $test_value ) {
+			$args = array_merge( $common_args, [
+				$test_key => $test_value,
+			] );
+
+			$query = new WP_User_Query();
+			$users = $query->query( $args );
+
+			$this->assertSame(
+				[
+					self::$users['admin']->ID,
+					self::$users['editor']->ID,
+					self::$users['author']->ID,
+					self::$users[ GUEST_ROLE ]->ID
+				],
+				$users,
+				"User IDs for combined attributed and non-attributed {$test_key} query are incorrect."
+			);
+		}
+	}
+
+}