diff --git a/src/wp-includes/link-template.php b/src/wp-includes/link-template.php
index 6b05040622..3ddcc49e15 100644
--- a/src/wp-includes/link-template.php
+++ b/src/wp-includes/link-template.php
@@ -152,7 +152,7 @@ function wp_force_plain_post_permalink( $post = null, $sample = null ) {
  *
  * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.
  * @param bool        $leavename Optional. Whether to keep post name or page name. Default false.
- * @return string|false The permalink URL or false if post does not exist.
+ * @return string|false The permalink URL. False if the post does not exist.
  */
 function get_the_permalink( $post = 0, $leavename = false ) {
 	return get_permalink( $post, $leavename );
@@ -165,7 +165,7 @@ function get_the_permalink( $post = 0, $leavename = false ) {
  *
  * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.
  * @param bool        $leavename Optional. Whether to keep post name or page name. Default false.
- * @return string|false The permalink URL or false if post does not exist.
+ * @return string|false The permalink URL. False if the post does not exist.
  */
 function get_permalink( $post = 0, $leavename = false ) {
 	$rewritecode = array(
@@ -314,15 +314,15 @@ function get_permalink( $post = 0, $leavename = false ) {
  * @param int|WP_Post $post      Optional. Post ID or post object. Default is the global `$post`.
  * @param bool        $leavename Optional. Whether to keep post name. Default false.
  * @param bool        $sample    Optional. Is it a sample permalink. Default false.
- * @return string|WP_Error The post permalink.
+ * @return string|false The post permalink URL. False if the post does not exist.
  */
 function get_post_permalink( $post = 0, $leavename = false, $sample = false ) {
 	global $wp_rewrite;
 
 	$post = get_post( $post );
 
-	if ( is_wp_error( $post ) ) {
-		return $post;
+	if ( ! $post ) {
+		return false;
 	}
 
 	$post_link = $wp_rewrite->get_extra_permastruct( $post->post_type );
@@ -3923,8 +3923,8 @@ function get_edit_profile_url( $user_id = 0, $scheme = 'admin' ) {
  * @since 4.6.0
  *
  * @param int|WP_Post $post Optional. Post ID or object. Default is global `$post`.
- * @return string|false The canonical URL, or false if the post does not exist or has not
- *                      been published yet.
+ * @return string|false The canonical URL. False if the post does not exist
+ *                      or has not been published yet.
  */
 function wp_get_canonical_url( $post = null ) {
 	$post = get_post( $post );
diff --git a/tests/phpunit/tests/link/getPostPermalink.php b/tests/phpunit/tests/link/getPostPermalink.php
new file mode 100644
index 0000000000..16d1da0bea
--- /dev/null
+++ b/tests/phpunit/tests/link/getPostPermalink.php
@@ -0,0 +1,18 @@
+<?php
+/**
+ * @group link
+ * @covers ::get_post_permalink
+ */
+class Tests_Link_GetPostPermalink extends WP_UnitTestCase {
+
+	public function test_get_post_permalink_should_return_string_on_success() {
+		$post = self::factory()->post->create();
+
+		$this->assertIsString( get_post_permalink( $post ) );
+	}
+
+	public function test_get_post_permalink_should_return_false_for_non_existing_post() {
+		$this->assertFalse( get_post_permalink( -1 ) );
+	}
+
+}