diff --git a/contrib/for-demos/test-webserver/test-webserver.go b/contrib/for-demos/test-webserver/test-webserver.go
index 74533f35d66..a34ce939114 100644
--- a/contrib/for-demos/test-webserver/test-webserver.go
+++ b/contrib/for-demos/test-webserver/test-webserver.go
@@ -39,7 +39,9 @@ func main() {
 		w.Header().Set("Access-Control-Allow-Origin", "*")
 		w.Header().Set("Access-Control-Allow-Credentials", "true")
 		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, OPTIONS")
-		w.Header().Set("Access-Control-Allow-Headers", "DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type")
+		w.Header().Set("Access-Control-Allow-Headers", "DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,Cache-Control,Content-Type")
+		// Disable If-Modified-Since so update-demo isn't broken by 304s
+		r.Header.Del("If-Modified-Since")
 		fs.ServeHTTP(w, r)
 	})
 
diff --git a/examples/update-demo/images/kitten/Dockerfile b/examples/update-demo/images/kitten/Dockerfile
index ea142cbc196..b053138b352 100644
--- a/examples/update-demo/images/kitten/Dockerfile
+++ b/examples/update-demo/images/kitten/Dockerfile
@@ -13,4 +13,5 @@
 # limitations under the License.
 
 FROM kubernetes/test-webserver
-ADD html/data.json html/kitten.jpg /
+COPY html/kitten.jpg kitten.jpg
+COPY html/data.json data.json
diff --git a/examples/update-demo/images/nautilus/Dockerfile b/examples/update-demo/images/nautilus/Dockerfile
index eb7115d0e2b..2904a107916 100644
--- a/examples/update-demo/images/nautilus/Dockerfile
+++ b/examples/update-demo/images/nautilus/Dockerfile
@@ -13,4 +13,5 @@
 # limitations under the License.
 
 FROM kubernetes/test-webserver
-ADD html/data.json html/nautilus.jpg /
+COPY html/nautilus.jpg nautilus.jpg
+COPY html/data.json data.json