diff --git a/.github/docker-images/ubuntu-18-x64/Dockerfile b/.github/docker-images/ubuntu-18-x64/Dockerfile
index c8eb699f9..aecda3e68 100644
--- a/.github/docker-images/ubuntu-18-x64/Dockerfile
+++ b/.github/docker-images/ubuntu-18-x64/Dockerfile
@@ -30,8 +30,8 @@ RUN apt-get update \
     libxml2-dev \
     libxmlsec1-dev \
     libffi-dev \
-    liblzma-dev \
-    && apt-get clean
+    software-properties-common \
+    liblzma-dev
 
 # Build Python 3.10 from source
 RUN cd /tmp \
@@ -43,16 +43,15 @@ RUN cd /tmp \
     && make altinstall \
     && cd / \
     && rm -rf /tmp/Python-3.10.12* \
-    && ln -sf /usr/local/bin/python3.10 /usr/bin/python3 \
+    && ln -sf /usr/local/bin/python3.10 /usr/local/bin/python \
     && /usr/local/bin/python3.10 --version
 
-# Install Go from default Ubuntu repository
+# Install Go and ensure system Python tools work
 RUN apt-get update \
     && apt-get -y install \
-    software-properties-common \
-    golang-go \
-    && apt-get clean \
-    && rm -rf /var/lib/apt/lists/*
+    python3-software-properties \
+    python3-apt \
+    golang-go
 
 ###############################################################################
 # Python/AWS CLI
diff --git a/README.md b/README.md
index f8c42d41a..aece5796c 100644
--- a/README.md
+++ b/README.md
@@ -299,7 +299,7 @@ debugging experience:
 * --build-dir=/path/to/other/git/repo - will jump to this directory before starting execution, helpful for debugging another project's
                                         configuration and build scripts
 
-When debugging builder from downstream CI (AWS common runtime repos), to use a branch of builder, you will need to change `BUILDER_VERSION` to the branch name of aws-crt-builder, and the `BUILDER_SOURCE` to be `channels` from `ci.yml`. Eg: for `aws-crt-java`, make those change to the [here](https://github.com/awslabs/aws-crt-java/blob/main/.github/workflows/ci.yml#L10-L11).
+When debugging builder from downstream CI (AWS common runtime repos), to use a branch of builder, you will need to change `BUILDER_VERSION` to the branch name of aws-crt-builder, and the `BUILDER_SOURCE` to be `channels` from `ci.yml`. Eg: for `aws-crt-java`, make those changes [here](https://github.com/awslabs/aws-crt-java/blob/eb3813e4da89709fe71611fd4fdf59a5eef40336/.github/workflows/ci.yml#L10-L11).
 
 ### Docker Images
 Each docker image has a script which will fetch the builder app baked into it, and will then call the builder with the arguments provided.