diff --git src/wp-includes/class-wp-oembed-controller.php src/wp-includes/class-wp-oembed-controller.php
index 0db5340..409cf18 100644
--- src/wp-includes/class-wp-oembed-controller.php
+++ src/wp-includes/class-wp-oembed-controller.php
@@ -67,12 +67,12 @@ final class WP_oEmbed_Controller {
 		$post_id = url_to_postid( $request['url'] );
 
 		/**
-		 * Filter the determined post id.
+		 * Filter the determined post ID.
 		 *
 		 * @since 4.4.0
 		 *
 		 * @param int    $post_id The post ID.
-		 * @param string $url     The requestd URL.
+		 * @param string $url     The requested URL.
 		 */
 		$post_id = apply_filters( 'oembed_request_post_id', $post_id, $request['url'] );
 
diff --git src/wp-includes/embed-functions.php src/wp-includes/embed-functions.php
index 2f430b5..ba8b08d 100644
--- src/wp-includes/embed-functions.php
+++ src/wp-includes/embed-functions.php
@@ -446,12 +446,12 @@ function get_oembed_endpoint_url( $permalink = '', $format = 'json' ) {
  *
  * @since 4.4.0
  *
- * @param int|WP_Post $post   Optional. Post ID or object. Default is global `$post`.
  * @param int         $width  The width for the response.
  * @param int         $height The height for the response.
+ * @param int|WP_Post $post   Optional. Post ID or object. Default is global `$post`.
  * @return string|false Embed code on success, false if post doesn't exist.
  */
-function get_post_embed_html( $post = null, $width, $height ) {
+function get_post_embed_html( $width, $height, $post = null ) {
 	$post = get_post( $post );
 
 	if ( ! $post ) {
@@ -510,11 +510,11 @@ JS;
  *
  * @since 4.4.0
  *
- * @param WP_Post|int $post  Optional. Post object or ID. Default is global `$post`.
+ * @param WP_Post|int $post  Post object or ID.
  * @param int         $width The requested width.
  * @return array|false Response data on success, false if post doesn't exist.
  */
-function get_oembed_response_data( $post = null, $width ) {
+function get_oembed_response_data( $post, $width ) {
 	$post = get_post( $post );
 
 	if ( ! $post ) {
@@ -590,7 +590,7 @@ function get_oembed_response_data_rich( $data, $post, $width, $height ) {
 	$data['width']  = absint( $width );
 	$data['height'] = absint( $height );
 	$data['type']   = 'rich';
-	$data['html']   = get_post_embed_html( $post, $width, $height );
+	$data['html']   = get_post_embed_html( $width, $height, $post );
 
 	// Add post thumbnail to response if available.
 	$thumbnail_id = false;
diff --git src/wp-includes/embed-template.php src/wp-includes/embed-template.php
index 120ae3b..5af9cb6 100644
--- src/wp-includes/embed-template.php
+++ src/wp-includes/embed-template.php
@@ -184,7 +184,7 @@ if ( have_posts() ) :
 							</p>
 						</div>
 						<div id="wp-embed-share-tab-html" class="wp-embed-share-tab" role="tabpanel" aria-labelledby="wp-embed-share-tab-button-html" aria-hidden="true">
-							<textarea class="wp-embed-share-input" tabindex="0" readonly><?php echo esc_textarea( get_post_embed_html( null, 600, 400 ) ); ?></textarea>
+							<textarea class="wp-embed-share-input" tabindex="0" readonly><?php echo esc_textarea( get_post_embed_html( 600, 400 ) ); ?></textarea>
 
 							<p class="wp-embed-share-description">
 								<?php _e( 'Copy and paste this code into your site to embed' ); ?>
diff --git tests/phpunit/tests/oembed/getResponseData.php tests/phpunit/tests/oembed/getResponseData.php
index 6dcdcbd..4a5c4f7 100644
--- tests/phpunit/tests/oembed/getResponseData.php
+++ tests/phpunit/tests/oembed/getResponseData.php
@@ -25,7 +25,7 @@ class Tests_oEmbed_Response_Data extends WP_UnitTestCase {
 			'type'          => 'rich',
 			'width'         => 400,
 			'height'        => 225,
-			'html'          => get_post_embed_html( $post, 400, 225 ),
+			'html'          => get_post_embed_html( 400, 225, $post ),
 		), $data );
 	}
 
@@ -54,7 +54,7 @@ class Tests_oEmbed_Response_Data extends WP_UnitTestCase {
 			'type'          => 'rich',
 			'width'         => 400,
 			'height'        => 225,
-			'html'          => get_post_embed_html( $post, 400, 225 ),
+			'html'          => get_post_embed_html( 400, 225, $post ),
 		), $data );
 	}
 
diff --git tests/phpunit/tests/oembed/template.php tests/phpunit/tests/oembed/template.php
index 644a6d5..ca07035 100644
--- tests/phpunit/tests/oembed/template.php
+++ tests/phpunit/tests/oembed/template.php
@@ -236,8 +236,8 @@ class Tests_Embed_Template extends WP_UnitTestCase {
 	}
 
 	function test_get_post_embed_html_non_existent_post() {
-		$this->assertFalse( get_post_embed_html( 0, 200, 200 ) );
-		$this->assertFalse( get_post_embed_html( null, 200, 200 ) );
+		$this->assertFalse( get_post_embed_html( 200, 200, 0 ) );
+		$this->assertFalse( get_post_embed_html( 200, 200 ) );
 	}
 
 	function test_get_post_embed_html() {
@@ -245,7 +245,7 @@ class Tests_Embed_Template extends WP_UnitTestCase {
 
 		$expected = '<iframe sandbox="allow-scripts" security="restricted" src="' . esc_url( get_post_embed_url( $post_id ) ) . '" width="200" height="200" title="Embedded WordPress Post" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"></iframe>';
 
-		$this->assertStringEndsWith( $expected, get_post_embed_html( $post_id, 200, 200 ) );
+		$this->assertStringEndsWith( $expected, get_post_embed_html( 200, 200, $post_id ) );
 	}
 
 	function test_add_host_js() {