diff --git a/docker/Dockerfile b/docker/Dockerfile
index 4a33d965e6..941c8588ce 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,9 +1,9 @@
 #== Ubuntu xenial is 16.04, i.e. FROM ubuntu:16.04
 # Find latest images at https://hub.docker.com/r/library/ubuntu/
 # Layer size: big: ~130 MB
-FROM ubuntu:xenial-20180123
+FROM ubuntu:xenial-20180228
 ENV UBUNTU_FLAVOR="xenial" \
-    UBUNTU_DATE="20180123"
+    UBUNTU_DATE="20180228"
 
 #== Ubuntu flavors - common
 RUN  echo "deb http://archive.ubuntu.com/ubuntu ${UBUNTU_FLAVOR} main universe\n" > /etc/apt/sources.list \
diff --git a/src/main/java/de/zalando/ep/zalenium/proxy/DockerSeleniumRemoteProxy.java b/src/main/java/de/zalando/ep/zalenium/proxy/DockerSeleniumRemoteProxy.java
index 9dfa131003..78c8c907da 100644
--- a/src/main/java/de/zalando/ep/zalenium/proxy/DockerSeleniumRemoteProxy.java
+++ b/src/main/java/de/zalando/ep/zalenium/proxy/DockerSeleniumRemoteProxy.java
@@ -321,6 +321,15 @@ private synchronized boolean increaseCounter() {
         return true;
     }
 
+    /*
+        When we shutdown the node because a test finished with a timeout, then we also set the test counter to the
+        max amount, otherwise there is a risk where a test is accepted while the node is shutting down.
+        This should only be invoked from the shutdownNode() method when the test had been idle.
+     */
+    private synchronized void stopReceivingTests() {
+        amountOfExecutedTests = maxTestSessions;
+    }
+
     private String getCapability(Map<String, Object> requestedCapability, String capabilityName, String defaultValue) {
         return Optional.ofNullable(requestedCapability.get(capabilityName)).orElse(defaultValue).toString();
     }
@@ -545,6 +554,7 @@ private void shutdownNode(boolean isTestIdle) {
 
         if (isTestIdle) {
             terminateIdleTest();
+            stopReceivingTests();
             shutdownReason = String.format("%s Marking the node as down because the test has been idle for more than %s seconds.",
                     getId(), getMaxTestIdleTimeSecs());
         }
diff --git a/src/main/java/de/zalando/ep/zalenium/registry/ZaleniumRegistry.java b/src/main/java/de/zalando/ep/zalenium/registry/ZaleniumRegistry.java
index 155efa4172..cabc52d304 100644
--- a/src/main/java/de/zalando/ep/zalenium/registry/ZaleniumRegistry.java
+++ b/src/main/java/de/zalando/ep/zalenium/registry/ZaleniumRegistry.java
@@ -57,16 +57,6 @@ public ZaleniumRegistry(Hub hub) {
         this.matcherThread.setUncaughtExceptionHandler(new UncaughtExceptionHandler());
     }
 
-    /**
-     * Creates a new {@link GridRegistry} that is not associated with a Hub and starts it.
-     *
-     * @return the registry
-     */
-    @SuppressWarnings({"NullableProblems"})
-    public static GridRegistry newInstance() {
-        return newInstance(null);
-    }
-
     /**
      * Creates a new {@link GridRegistry} and starts it.
      *