diff --git a/.zuul.yaml b/.zuul.yaml
index f20329b7b6..a8c2354920 100644
--- a/.zuul.yaml
+++ b/.zuul.yaml
@@ -63,6 +63,12 @@
             uploaded (it will be tagged with this in the local
             registry).
 
+         .. zuul:jobvar:: path
+
+            Optional; if supplied, the directory that should be passed to
+            docker build. Useful for building images with a Dockerfile
+            in the context directory but a source repository elsewhere.
+
     abstract: true
     pre-run: playbooks/zuul/build-image/pre.yaml
     run: playbooks/zuul/build-image/run.yaml
diff --git a/playbooks/zuul/build-image/run.yaml b/playbooks/zuul/build-image/run.yaml
index afe1b1e2d8..02b62dc1bf 100644
--- a/playbooks/zuul/build-image/run.yaml
+++ b/playbooks/zuul/build-image/run.yaml
@@ -1,7 +1,7 @@
 - hosts: all
   tasks:
     - name: Build a docker image
-      command: "docker build . {{ target | default(false) | ternary('--target ', '') }}{{ target | default('') }} --tag {{ item.repository }}:change_{{ zuul.change }}"
+      command: "docker build {{ item.path | default('.') }} -f Dockerfile {{ target | default(false) | ternary('--target ', '') }}{{ target | default('') }} --tag {{ item.repository }}:change_{{ zuul.change }}"
       args:
         chdir: "{{ zuul.project.src_dir }}/{{ item.context }}"
       loop: "{{ images }}"