diff --git a/prow/cluster/jobs/istio/istio/istio.istio.master.gen.yaml b/prow/cluster/jobs/istio/istio/istio.istio.master.gen.yaml
index c27da82f32f..8bd4db88896 100644
--- a/prow/cluster/jobs/istio/istio/istio.istio.master.gen.yaml
+++ b/prow/cluster/jobs/istio/istio/istio.istio.master.gen.yaml
@@ -1721,7 +1721,7 @@ postsubmits:
       preset-release-pipeline: "true"
     name: build-base-images_istio_postsubmit
     path_alias: istio.io/istio
-    run_if_changed: ^docker/Dockerfile.base$
+    run_if_changed: ^(docker|pkg/.*)/Dockerfile.([a-zA-Z0-9_]+_)?base(_[a-zA-Z0-9_]+)?$
     spec:
       containers:
       - command:
diff --git a/prow/config/jobs/istio.yaml b/prow/config/jobs/istio.yaml
index 736508e70e1..e8935410d6e 100644
--- a/prow/config/jobs/istio.yaml
+++ b/prow/config/jobs/istio.yaml
@@ -351,7 +351,7 @@ jobs:
   - name: build-base-images
     repos: [istio/release-builder@master]
     types: [postsubmit]
-    regex: '^docker/Dockerfile.base$'
+    regex: '^(docker|pkg/.*)/Dockerfile.([a-zA-Z0-9_]+_)?base(_[a-zA-Z0-9_]+)?$'
     env:
     - name: BUILD_BASE_IMAGES
       value: "true"