diff --git a/docs/man/man1/kubectl-proxy.1 b/docs/man/man1/kubectl-proxy.1
index a8ff3050848..4934970e8e6 100644
--- a/docs/man/man1/kubectl-proxy.1
+++ b/docs/man/man1/kubectl-proxy.1
@@ -51,7 +51,7 @@ The above lets you 'curl localhost:8001/custom/api/v1/pods'
     The IP address on which to serve on.
 
 .PP
-\fB\-\-api\-prefix\fP="/api/"
+\fB\-\-api\-prefix\fP="/"
     Prefix to serve the proxied API under.
 
 .PP
diff --git a/docs/user-guide/kubectl/kubectl_proxy.md b/docs/user-guide/kubectl/kubectl_proxy.md
index eb24547fb55..19e3a5f59d3 100644
--- a/docs/user-guide/kubectl/kubectl_proxy.md
+++ b/docs/user-guide/kubectl/kubectl_proxy.md
@@ -80,7 +80,7 @@ $ kubectl proxy --api-prefix=/k8s-api
       --accept-hosts="^localhost$,^127\\.0\\.0\\.1$,^\\[::1\\]$": Regular expression for hosts that the proxy should accept.
       --accept-paths="^/.*": Regular expression for paths that the proxy should accept.
       --address="127.0.0.1": The IP address on which to serve on.
-      --api-prefix="/api/": Prefix to serve the proxied API under.
+      --api-prefix="/": Prefix to serve the proxied API under.
       --disable-filter[=false]: If true, disable request filtering in the proxy. This is dangerous, and can leave you vulnerable to XSRF attacks, when used with an accessible port.
   -p, --port=8001: The port on which to run the proxy. Set to 0 to pick a random port.
       --reject-methods="POST,PUT,PATCH": Regular expression for HTTP methods that the proxy should reject.
diff --git a/hack/test-cmd.sh b/hack/test-cmd.sh
index 85586ecea9d..341880dd3e5 100755
--- a/hack/test-cmd.sh
+++ b/hack/test-cmd.sh
@@ -163,6 +163,7 @@ KUBE_API_VERSIONS="v1,extensions/v1beta1" "${KUBE_OUTPUT_HOSTBIN}/kube-apiserver
   --kubelet-port=${KUBELET_PORT} \
   --runtime-config=api/v1 \
   --cert-dir="${TMPDIR:-/tmp/}" \
+  --runtime_config="extensions/v1beta1=true" \
   --service-cluster-ip-range="10.0.0.0/24" 1>&2 &
 APISERVER_PID=$!
 
@@ -217,22 +218,20 @@ runTests() {
   #######################
 
   # Make sure the UI can be proxied
-  start-proxy --api-prefix=/
+  start-proxy
   check-curl-proxy-code /ui 301
   check-curl-proxy-code /metrics 200
-  if [[ -n "${version}" ]]; then
-    check-curl-proxy-code /api/${version}/namespaces 200
-  fi
-  stop-proxy
-
-  # Default proxy locks you into the /api path (legacy behavior)
-  start-proxy
-  check-curl-proxy-code /ui 404
-  check-curl-proxy-code /metrics 404
   check-curl-proxy-code /api/ui 404
   if [[ -n "${version}" ]]; then
     check-curl-proxy-code /api/${version}/namespaces 200
   fi
+  check-curl-proxy-code /healthz/ 200
+  stop-proxy
+
+  # Make sure the in-development api is accessible by default
+  start-proxy
+  check-curl-proxy-code /apis 200
+  check-curl-proxy-code /apis/extensions/ 200
   stop-proxy
 
   # Custom paths let you see everything.
diff --git a/pkg/kubectl/cmd/proxy.go b/pkg/kubectl/cmd/proxy.go
index 5ec9114f16d..130e2ae5967 100644
--- a/pkg/kubectl/cmd/proxy.go
+++ b/pkg/kubectl/cmd/proxy.go
@@ -71,7 +71,7 @@ The above lets you 'curl localhost:8001/custom/api/v1/pods'
 	}
 	cmd.Flags().StringP("www", "w", "", "Also serve static files from the given directory under the specified prefix.")
 	cmd.Flags().StringP("www-prefix", "P", "/static/", "Prefix to serve static files under, if static file directory is specified.")
-	cmd.Flags().StringP("api-prefix", "", "/api/", "Prefix to serve the proxied API under.")
+	cmd.Flags().StringP("api-prefix", "", "/", "Prefix to serve the proxied API under.")
 	cmd.Flags().String("accept-paths", kubectl.DefaultPathAcceptRE, "Regular expression for paths that the proxy should accept.")
 	cmd.Flags().String("reject-paths", kubectl.DefaultPathRejectRE, "Regular expression for paths that the proxy should reject.")
 	cmd.Flags().String("accept-hosts", kubectl.DefaultHostAcceptRE, "Regular expression for hosts that the proxy should accept.")