diff --git a/src/wp-admin/includes/file.php b/src/wp-admin/includes/file.php
index edb3d99361..2e4493e8d8 100644
--- a/src/wp-admin/includes/file.php
+++ b/src/wp-admin/includes/file.php
@@ -1705,7 +1705,7 @@ function copy_dir( $from, $to, $skip_list = array() ) {
 	$to   = trailingslashit( $to );
 
 	foreach ( (array) $dirlist as $filename => $fileinfo ) {
-		if ( in_array( $filename, $skip_list ) ) {
+		if ( in_array( $filename, $skip_list, true ) ) {
 			continue;
 		}
 
diff --git a/src/wp-admin/includes/update-core.php b/src/wp-admin/includes/update-core.php
index 1cb915f858..8df6150356 100644
--- a/src/wp-admin/includes/update-core.php
+++ b/src/wp-admin/includes/update-core.php
@@ -1312,7 +1312,7 @@ function _copy_dir( $from, $to, $skip_list = array() ) {
 	$to   = trailingslashit( $to );
 
 	foreach ( (array) $dirlist as $filename => $fileinfo ) {
-		if ( in_array( $filename, $skip_list ) ) {
+		if ( in_array( $filename, $skip_list, true ) ) {
 			continue;
 		}