diff --git a/src/wp-includes/embed.php b/src/wp-includes/embed.php
index 338c6a041b..eb71951d34 100644
--- a/src/wp-includes/embed.php
+++ b/src/wp-includes/embed.php
@@ -374,7 +374,7 @@ function wp_oembed_add_host_js() {
  * @return string Embed markup (without modifications).
  */
 function wp_maybe_enqueue_oembed_host_js( $html ) {
-	if ( preg_match( '/<blockquote\s[^>]*wp-embedded-content/', $html ) ) {
+	if ( preg_match( '/<blockquote\s[^>]*?wp-embedded-content/', $html ) ) {
 		wp_enqueue_script( 'wp-embed' );
 	}
 	return $html;
@@ -471,11 +471,7 @@ function get_post_embed_html( $width, $height, $post = null ) {
 	$secret     = wp_generate_password( 10, false );
 	$embed_url .= "#?secret={$secret}";
 
-	$output = wp_get_inline_script_tag(
-		file_get_contents( ABSPATH . WPINC . '/js/wp-embed' . wp_scripts_get_suffix() . '.js' )
-	);
-
-	$output .= sprintf(
+	$output = sprintf(
 		'<blockquote class="wp-embedded-content" data-secret="%1$s"><a href="%2$s">%3$s</a></blockquote>',
 		esc_attr( $secret ),
 		esc_url( get_permalink( $post ) ),
@@ -498,6 +494,15 @@ function get_post_embed_html( $width, $height, $post = null ) {
 		esc_attr( $secret )
 	);
 
+	// Note that the script must be placed after the <blockquote> and <iframe> due to a regexp parsing issue in
+	// `wp_filter_oembed_result()`. Because of the regex pattern starts with `|(<blockquote>.*?</blockquote>)?.*|`
+	// wherein the <blockquote> is marked as being optional, if it is not at the beginning of the string then the group
+	// will fail to match and everything will be matched by `.*` and not included in the group. This regex issue goes
+	// back to WordPress 4.4, so in order to not break older installs this script must come at the end.
+	$output .= wp_get_inline_script_tag(
+		file_get_contents( ABSPATH . WPINC . '/js/wp-embed' . wp_scripts_get_suffix() . '.js' )
+	);
+
 	/**
 	 * Filters the embed HTML output for a given post.
 	 *
diff --git a/tests/phpunit/tests/oembed/template.php b/tests/phpunit/tests/oembed/template.php
index 8146846791..f24b421a87 100644
--- a/tests/phpunit/tests/oembed/template.php
+++ b/tests/phpunit/tests/oembed/template.php
@@ -300,7 +300,9 @@ class Tests_Embed_Template extends WP_UnitTestCase {
 		$actual   = get_post_embed_html( 200, 200, $post_id );
 		$actual   = preg_replace( '/secret=("?)\w+\1/', 'secret=__SECRET__', $actual );
 
-		$this->assertStringEndsWith( $expected, $actual );
+		$this->assertStringStartsWith( '<blockquote class="wp-embedded-content" data-secret=__SECRET__>', $actual );
+		$this->assertStringContainsString( $expected, $actual );
+		$this->assertStringEndsWith( '</script>', trim( $actual ) );
 	}
 
 	/** @covers ::wp_oembed_add_host_js() */