diff --git a/oss-drivers/php-mssql/Dockerfile b/oss-drivers/php-mssql/Dockerfile
index 9abd2323..34d1ba21 100644
--- a/oss-drivers/php-mssql/Dockerfile
+++ b/oss-drivers/php-mssql/Dockerfile
@@ -1,6 +1,6 @@
 # php-mssql
 # PHP runtime with pdo_sqlsrv to connect to SQL Server
-FROM ubuntu:16.04
+FROM ubuntu:xenial-20210416
 
 # apt-get and system utilities
 RUN apt-get update && apt-get install -y \