diff --git a/wp-admin/includes/class-wp-upgrader.php b/wp-admin/includes/class-wp-upgrader.php
index 532d027ba6..32e74c0ecd 100644
--- a/wp-admin/includes/class-wp-upgrader.php
+++ b/wp-admin/includes/class-wp-upgrader.php
@@ -1458,4 +1458,10 @@ class File_Upload_Upgrader {
 			$this->package = $uploads['basedir'] . '/' . $this->filename;
 		}
 	}
+
+	function cleanup() {
+		if ( file_exists($this->package) )
+			return @unlink($this->package);
+		return true;
+	}
 }
\ No newline at end of file
diff --git a/wp-admin/update.php b/wp-admin/update.php
index e529064eed..cbaee95859 100644
--- a/wp-admin/update.php
+++ b/wp-admin/update.php
@@ -140,6 +140,8 @@ if ( isset($_GET['action']) ) {
 		$upgrader = new Plugin_Upgrader( new Plugin_Installer_Skin( compact('type', 'title', 'nonce', 'url') ) );
 		$upgrader->install( $file_upload->package );
 
+		$file_upload->cleanup();
+
 		include(ABSPATH . 'wp-admin/admin-footer.php');
 
 	} elseif ( 'upgrade-theme' == $action ) {
@@ -242,6 +244,8 @@ if ( isset($_GET['action']) ) {
 		$upgrader = new Theme_Upgrader( new Theme_Installer_Skin( compact('type', 'title', 'nonce', 'url') ) );
 		$upgrader->install( $file_upload->package );
 
+		$file_upload->cleanup();
+
 		include(ABSPATH . 'wp-admin/admin-footer.php');
 
 	} else {