diff --git a/examples/cluster-dns/images/backend/Dockerfile b/examples/cluster-dns/images/backend/Dockerfile
index 915a2d19020..d45858468e9 100644
--- a/examples/cluster-dns/images/backend/Dockerfile
+++ b/examples/cluster-dns/images/backend/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:2.7
+FROM python:2.7-slim
 
 COPY . /dns-backend
 WORKDIR /dns-backend
diff --git a/examples/cluster-dns/images/frontend/Dockerfile b/examples/cluster-dns/images/frontend/Dockerfile
index 6046b7e1afb..a2662881394 100644
--- a/examples/cluster-dns/images/frontend/Dockerfile
+++ b/examples/cluster-dns/images/frontend/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:2.7
+FROM python:2.7-slim
 
 RUN pip install requests