diff --git a/wp-admin/plugin-editor.php b/wp-admin/plugin-editor.php
index 78eac87f92..1b0b714c32 100644
--- a/wp-admin/plugin-editor.php
+++ b/wp-admin/plugin-editor.php
@@ -162,7 +162,7 @@ if ( ! empty( $posted_content ) ) {
 	$content = file_get_contents( $real_file );
 }
 
-if ( '.php' === substr( $real_file, strrpos( $real_file, '.' ) ) ) {
+if ( str_ends_with( $real_file, '.php' ) ) {
 	$functions = wp_doc_link_parse( $content );
 
 	if ( ! empty( $functions ) ) {
diff --git a/wp-admin/theme-editor.php b/wp-admin/theme-editor.php
index 345d00017f..07de6269a7 100644
--- a/wp-admin/theme-editor.php
+++ b/wp-admin/theme-editor.php
@@ -161,7 +161,7 @@ if ( ! empty( $posted_content ) ) {
 	$f       = fopen( $file, 'r' );
 	$content = fread( $f, filesize( $file ) );
 
-	if ( '.php' === substr( $file, strrpos( $file, '.' ) ) ) {
+	if ( str_ends_with( $file, '.php' ) ) {
 		$functions = wp_doc_link_parse( $content );
 
 		if ( ! empty( $functions ) ) {
diff --git a/wp-includes/class-wp-rewrite.php b/wp-includes/class-wp-rewrite.php
index 35598c3d80..1963f21b0c 100644
--- a/wp-includes/class-wp-rewrite.php
+++ b/wp-includes/class-wp-rewrite.php
@@ -1907,7 +1907,7 @@ class WP_Rewrite {
 		unset( $this->feed_structure );
 		unset( $this->comment_feed_structure );
 
-		$this->use_trailing_slashes = ( '/' === substr( $this->permalink_structure, -1, 1 ) );
+		$this->use_trailing_slashes = str_ends_with( $this->permalink_structure, '/' );
 
 		// Enable generic rules for pages if permalink structure doesn't begin with a wildcard.
 		if ( preg_match( '/^[^%]*%(?:postname|category|tag|author)%/', $this->permalink_structure ) ) {
diff --git a/wp-includes/load.php b/wp-includes/load.php
index 6e7ab4cbcd..9d20aff3d7 100644
--- a/wp-includes/load.php
+++ b/wp-includes/load.php
@@ -877,7 +877,7 @@ function wp_get_active_and_valid_plugins() {
 
 	foreach ( $active_plugins as $plugin ) {
 		if ( ! validate_file( $plugin )                     // $plugin must validate as file.
-			&& '.php' === substr( $plugin, -4 )             // $plugin must end with '.php'.
+			&& str_ends_with( $plugin, '.php' )             // $plugin must end with '.php'.
 			&& file_exists( WP_PLUGIN_DIR . '/' . $plugin ) // $plugin must exist.
 			// Not already included as a network plugin.
 			&& ( ! $network_plugins || ! in_array( WP_PLUGIN_DIR . '/' . $plugin, $network_plugins, true ) )
diff --git a/wp-includes/rest-api.php b/wp-includes/rest-api.php
index d9dd834c90..70dc9deec6 100644
--- a/wp-includes/rest-api.php
+++ b/wp-includes/rest-api.php
@@ -467,7 +467,7 @@ function get_rest_url( $blog_id = null, $path = '/', $scheme = 'rest' ) {
 		$url = trailingslashit( get_home_url( $blog_id, '', $scheme ) );
 		// nginx only allows HTTP/1.0 methods when redirecting from / to /index.php.
 		// To work around this, we manually add index.php to the URL, avoiding the redirect.
-		if ( 'index.php' !== substr( $url, 9 ) ) {
+		if ( ! str_ends_with( $url, 'index.php' ) ) {
 			$url .= 'index.php';
 		}
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index e2541215c8..c41589188d 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.3-alpha-56013';
+$wp_version = '6.3-alpha-56014';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.