diff --git a/.clang-format b/.clang-format
index 26ac15c1..0d0670af 100644
--- a/.clang-format
+++ b/.clang-format
@@ -22,7 +22,7 @@ BreakBeforeBinaryOperators: NonAssignment
 BreakBeforeBraces: Custom
 # fails if all initializers fit on one line
 BreakConstructorInitializers: AfterColon
-ColumnLimit: 90
+ColumnLimit: 85
 # fails
 ConstructorInitializerIndentWidth: 2
 IncludeBlocks: Preserve
diff --git a/Dockerfile.centos7 b/Dockerfile.centos7
index 8857a99c..cdcd6037 100644
--- a/Dockerfile.centos7
+++ b/Dockerfile.centos7
@@ -11,7 +11,7 @@ RUN sed -i s/mirror.centos.org/vault.centos.org/g /etc/yum.repos.d/*.repo \
 RUN sed -i s/mirror.centos.org/vault.centos.org/g /etc/yum.repos.d/*.repo \
     && sed -i s/^#.*baseurl=http/baseurl=http/g /etc/yum.repos.d/*.repo \
     && sed -i s/^mirrorlist=http/#mirrorlist=http/g /etc/yum.repos.d/*.repo \ 
-    && yum install -y devtoolset-11 wget cmake3 make eigen3-devel tcl swig3 flex zlib-devel valgrind \
+    && yum install -y devtoolset-11 git wget cmake3 make eigen3-devel tcl swig3 flex zlib-devel valgrind \
     && yum clean -y all
 
 RUN ln -sf /usr/bin/cmake3 /usr/bin/cmake
diff --git a/README.md b/README.md
index 6814119f..8323cf74 100644
--- a/README.md
+++ b/README.md
@@ -184,13 +184,23 @@ files in the build directory.
 
 ## Build with Docker
 
-An alternative way to build and run OpenSTA is with
+AN alternative way to build and run OpenSTA is with
 [Docker](https://www.docker.com).  After installing Docker, the
 following command builds a Docker image.
 
 ```
 cd OpenSTA
 docker build --file Dockerfile.ubuntu22.04 --tag opensta_ubuntu22.04 .
+or
+docker build --file Dockerfile.centos7 --tag opensta_centos7 .
+```
+
+The centos7 build on mac/OsX with ARM processorts requires the platform
+to be specified.
+
+```
+docker build --file Dockerfile.centos7 --platform=linux/amd64 --tag opensta_centos7 .
+
 ```
 
 To run a docker container using the OpenSTA image, use the -v option