diff --git a/wp-admin/includes/upgrade.php b/wp-admin/includes/upgrade.php
index 9014d97100..72f3536578 100644
--- a/wp-admin/includes/upgrade.php
+++ b/wp-admin/includes/upgrade.php
@@ -874,7 +874,7 @@ function upgrade_all() {
 		upgrade_550();
 	}
 
-	if ( $wp_current_db_version < 49632 ) {
+	if ( $wp_current_db_version < 49735 ) {
 		upgrade_560();
 	}
 
@@ -2274,6 +2274,10 @@ function upgrade_560() {
 		 */
 		save_mod_rewrite_rules();
 	}
+
+	if ( $wp_current_db_version < 49735 ) {
+		delete_transient( 'dirsize_cache' );
+	}
 }
 
 /**
diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 3b0dfda4bf..7219d768a9 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -7626,8 +7626,6 @@ function get_dirsize( $directory, $max_execution_time = null ) {
  */
 function recurse_dirsize( $directory, $exclude = null, $max_execution_time = null, &$directory_cache = null ) {
 	$directory  = untrailingslashit( $directory );
-	$cache_path = untrailingslashit( str_replace( ABSPATH, '', $directory ) );
-
 	$save_cache = false;
 
 	if ( ! isset( $directory_cache ) ) {
@@ -7635,8 +7633,8 @@ function recurse_dirsize( $directory, $exclude = null, $max_execution_time = nul
 		$save_cache      = true;
 	}
 
-	if ( isset( $directory_cache[ $cache_path ] ) ) {
-		return $directory_cache[ $cache_path ];
+	if ( isset( $directory_cache[ $directory ] ) && is_int( $directory_cache[ $directory ] ) ) {
+		return $directory_cache[ $directory ];
 	}
 
 	if ( ! file_exists( $directory ) || ! is_dir( $directory ) || ! is_readable( $directory ) ) {
@@ -7705,7 +7703,7 @@ function recurse_dirsize( $directory, $exclude = null, $max_execution_time = nul
 		}
 	}
 
-	$directory_cache[ $cache_path ] = $size;
+	$directory_cache[ $directory ] = $size;
 
 	// Only write the transient on the top level call and not on recursive calls.
 	if ( $save_cache ) {
@@ -7731,12 +7729,12 @@ function clean_dirsize_cache( $path ) {
 		return;
 	}
 
-	$cache_path = untrailingslashit( str_replace( ABSPATH, '', $path ) );
-	unset( $directory_cache[ $cache_path ] );
+	$path = untrailingslashit( $path );
+	unset( $directory_cache[ $path ] );
 
-	while ( DIRECTORY_SEPARATOR !== $cache_path && '.' !== $cache_path && '..' !== $cache_path ) {
-		$cache_path = dirname( $cache_path );
-		unset( $directory_cache[ $cache_path ] );
+	while ( DIRECTORY_SEPARATOR !== $path && '.' !== $path && '..' !== $path ) {
+		$path = dirname( $path );
+		unset( $directory_cache[ $path ] );
 	}
 
 	set_transient( 'dirsize_cache', $directory_cache );
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 902303bbdf..7ec9f69aed 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,14 +13,14 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.7-alpha-49741';
+$wp_version = '5.7-alpha-49744';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.
  *
  * @global int $wp_db_version
  */
-$wp_db_version = 49632;
+$wp_db_version = 49735;
 
 /**
  * Holds the TinyMCE version.