diff --git a/docker/blocks/mssql/build/Dockerfile b/docker/blocks/mssql/build/Dockerfile
index 2de0058907f..ac19463538c 100644
--- a/docker/blocks/mssql/build/Dockerfile
+++ b/docker/blocks/mssql/build/Dockerfile
@@ -1,4 +1,4 @@
-FROM microsoft/mssql-server-linux:latest
+FROM microsoft/mssql-server-linux:2017-CU4
 WORKDIR /usr/setup
 COPY . /usr/setup
 RUN chmod +x /usr/setup/setup.sh