diff --git a/tasks/modify_image.yml b/tasks/modify_image.yml
index 9464aa7..567504e 100644
--- a/tasks/modify_image.yml
+++ b/tasks/modify_image.yml
@@ -8,11 +8,6 @@
       - modify_dir_path is defined
       - modify_dir_path | length > 0
 
-- name: Set default modified_append_tag
-  set_fact:
-    modified_append_tag: "{{ lookup('pipe','date +-modified-%Y%m%d%H%M%S') }}"
-  when: modified_append_tag is undefined
-
 - name: Create Dockerfile tempfile name
   tempfile:
     path: "{{ modify_dir_path }}"
diff --git a/tasks/precheck.yml b/tasks/precheck.yml
index adf54fd..6649784 100644
--- a/tasks/precheck.yml
+++ b/tasks/precheck.yml
@@ -7,3 +7,8 @@
 - name: Ensure that container_build_tool is correctly set
   fail: msg="{{ container_build_tool }} is not a valid value for container_build_tool. Pick docker or buildah."
   when: container_build_tool not in ['docker', 'buildah']
+
+- name: Set default modified_append_tag
+  set_fact:
+    modified_append_tag: "{{ lookup('pipe','date +-modified-%Y%m%d%H%M%S') }}"
+  when: modified_append_tag is undefined
diff --git a/tasks/yum_update.yml b/tasks/yum_update.yml
index 13e27b0..47497ac 100644
--- a/tasks/yum_update.yml
+++ b/tasks/yum_update.yml
@@ -2,55 +2,8 @@
   tags:
     - always
 
-- import_tasks: get_original_user.yml
+- import_tasks: yum_update_buildah.yml
+  when: container_build_tool == 'buildah'
 
-- name: Create image build context directory
-  tempfile:
-    state: directory
-    prefix: tripleo-modify-image
-  register: context_dir
-
-- name: Set modify_dir_path
-  set_fact:
-    modify_dir_path: "{{ context_dir.path }}"
-
-- name: Copy local file repos to context directory
-  shell: |
-    #!/bin/sh
-    set -ex
-
-    cp -a {{ yum_repos_dir_path }} {{ modify_dir_path }}/yum.repos.d
-
-    # discover repos with local packages
-    repos=$(sed -n 's/baseurl=file:\/\///p' {{ yum_repos_dir_path }}/*.repo)
-
-    mkdir repos
-    for repo in $repos ; do
-        if [ -d $repo ]; then
-            target_dir=repos$repo
-            echo "copying $repo to $target_dir"
-            mkdir -p $target_dir
-            cp -a $repo/* $target_dir
-        fi
-    done
-  args:
-    chdir: "{{ modify_dir_path }}"
-  when: yum_repos_dir_path is defined
-
-- name: Write Dockerfile to {{ modify_dir_path }}
-  template:
-    src: Dockerfile-yum.j2
-    dest: "{{ modify_dir_path }}/Dockerfile"
-
-- name: Write yum_update.sh
-  copy:
-    src: yum_update.sh
-    dest: "{{ modify_dir_path }}/yum_update.sh"
-    mode: '0555'
-
-- include_tasks: modify_image.yml
-
-- name: Clean modify directory
-  file:
-    state: absent
-    path: "{{ modify_dir_path }}"
+- import_tasks: yum_update_docker.yml
+  when: container_build_tool == 'docker'
diff --git a/tasks/yum_update_buildah.yml b/tasks/yum_update_buildah.yml
new file mode 100644
index 0000000..36f6350
--- /dev/null
+++ b/tasks/yum_update_buildah.yml
@@ -0,0 +1,49 @@
+- import_tasks: precheck.yml
+  tags:
+    - always
+
+- name: From image {{ source_image }}
+  command: buildah from {{ source_image }}
+  register: from_image_cmd
+
+- name: Set from_image
+  set_fact:
+    from_image: "{{ from_image_cmd.stdout }}"
+
+- name: Run buildah config
+  command: >
+    buildah config
+      --label modified_append_tag={{ modified_append_tag }}
+      --workingdir / {{ from_image }}
+
+- name: Copy yum_update.sh
+  command: >
+    buildah copy
+      {{ from_image }}
+      files/yum_update.sh /tmp/yum_update.sh
+
+- name: List file repos
+  shell: sed -n 's|baseurl=file://||p' *.repo
+  args:
+    chdir: "{{ yum_repos_dir_path }}"
+  register: file_repos
+
+- name: Run yum_update.sh
+  command: >
+    buildah run
+      --volume {{ yum_repos_dir_path }}:/etc/yum.repos.d
+      {% for repo in file_repos.stdout_lines %}
+        {% if repo|exists %}
+          --volume {{ repo }}:{{ repo }}
+        {% endif %}
+      {% endfor %}
+      --user root
+      --net host
+      {{ from_image }}
+      /tmp/yum_update.sh "{{ update_repo }}"
+
+- name: Commit changes to image {{ target_image | default(source_image) }}
+  command: >
+    buildah commit
+      {{ from_image }}
+      {{ target_image | default(source_image) }}
diff --git a/tasks/yum_update_docker.yml b/tasks/yum_update_docker.yml
new file mode 100644
index 0000000..13e27b0
--- /dev/null
+++ b/tasks/yum_update_docker.yml
@@ -0,0 +1,56 @@
+- import_tasks: precheck.yml
+  tags:
+    - always
+
+- import_tasks: get_original_user.yml
+
+- name: Create image build context directory
+  tempfile:
+    state: directory
+    prefix: tripleo-modify-image
+  register: context_dir
+
+- name: Set modify_dir_path
+  set_fact:
+    modify_dir_path: "{{ context_dir.path }}"
+
+- name: Copy local file repos to context directory
+  shell: |
+    #!/bin/sh
+    set -ex
+
+    cp -a {{ yum_repos_dir_path }} {{ modify_dir_path }}/yum.repos.d
+
+    # discover repos with local packages
+    repos=$(sed -n 's/baseurl=file:\/\///p' {{ yum_repos_dir_path }}/*.repo)
+
+    mkdir repos
+    for repo in $repos ; do
+        if [ -d $repo ]; then
+            target_dir=repos$repo
+            echo "copying $repo to $target_dir"
+            mkdir -p $target_dir
+            cp -a $repo/* $target_dir
+        fi
+    done
+  args:
+    chdir: "{{ modify_dir_path }}"
+  when: yum_repos_dir_path is defined
+
+- name: Write Dockerfile to {{ modify_dir_path }}
+  template:
+    src: Dockerfile-yum.j2
+    dest: "{{ modify_dir_path }}/Dockerfile"
+
+- name: Write yum_update.sh
+  copy:
+    src: yum_update.sh
+    dest: "{{ modify_dir_path }}/yum_update.sh"
+    mode: '0555'
+
+- include_tasks: modify_image.yml
+
+- name: Clean modify directory
+  file:
+    state: absent
+    path: "{{ modify_dir_path }}"