diff --git a/CHANGES.txt b/CHANGES.txt
index 10bd2da1d05..8013b0e4bcf 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -451,6 +451,8 @@ Release 0.92.0 - Unreleased
    HBASE-4553  The update of .tableinfo is not atomic; we remove then rename
    HBASE-4725  NPE in AM#updateTimers
    HBASE-4745  LRU statistics thread should be a daemon
+   HBASE-4749  TestMasterFailover#testMasterFailoverWithMockedRITOnDeadRS
+               occasionally fails
 
   TESTS
    HBASE-4450  test for number of blocks read: to serve as baseline for expected
diff --git a/src/main/java/org/apache/hadoop/hbase/master/HMaster.java b/src/main/java/org/apache/hadoop/hbase/master/HMaster.java
index 0d0e4c56694..7abe5cb3e86 100644
--- a/src/main/java/org/apache/hadoop/hbase/master/HMaster.java
+++ b/src/main/java/org/apache/hadoop/hbase/master/HMaster.java
@@ -1319,8 +1319,10 @@ implements HMasterInterface, HMasterRegionInterface, MasterServices, Server {
     LOG.info(why);
     this.stopped = true;
     // If we are a backup master, we need to interrupt wait
-    synchronized (this.activeMasterManager.clusterHasActiveMaster) {
-      this.activeMasterManager.clusterHasActiveMaster.notifyAll();
+    if (this.activeMasterManager != null) {
+      synchronized (this.activeMasterManager.clusterHasActiveMaster) {
+        this.activeMasterManager.clusterHasActiveMaster.notifyAll();
+      }
     }
   }
 
diff --git a/src/test/java/org/apache/hadoop/hbase/master/TestMasterFailover.java b/src/test/java/org/apache/hadoop/hbase/master/TestMasterFailover.java
index 722c086d3e2..ac1b01c8301 100644
--- a/src/test/java/org/apache/hadoop/hbase/master/TestMasterFailover.java
+++ b/src/test/java/org/apache/hadoop/hbase/master/TestMasterFailover.java
@@ -50,6 +50,7 @@ import org.apache.hadoop.hbase.regionserver.HRegionServer;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.hbase.util.FSTableDescriptors;
 import org.apache.hadoop.hbase.util.JVMClusterUtil;
+import org.apache.hadoop.hbase.util.Threads;
 import org.apache.hadoop.hbase.util.JVMClusterUtil.MasterThread;
 import org.apache.hadoop.hbase.util.JVMClusterUtil.RegionServerThread;
 import org.apache.hadoop.hbase.zookeeper.ZKAssign;
@@ -706,10 +707,13 @@ public class TestMasterFailover {
     assertEquals(2, cluster.countServedRegions());
 
     // The first RS will stay online
-    HRegionServer hrs = cluster.getRegionServer(0);
+    List<RegionServerThread> regionservers =
+      cluster.getRegionServerThreads();
+    HRegionServer hrs = regionservers.get(0).getRegionServer();
 
     // The second RS is going to be hard-killed
-    HRegionServer hrsDead = cluster.getRegionServer(1);
+    RegionServerThread hrsDeadThread = regionservers.get(1);
+    HRegionServer hrsDead = hrsDeadThread.getRegionServer();
     ServerName deadServerName = hrsDead.getServerName();
 
     // we'll need some regions to already be assigned out properly on live RS
@@ -916,7 +920,11 @@ public class TestMasterFailover {
     hrsDead.abort("Killing for unit test");
     log("RS " + deadServerName + " killed");
 
-    // Start up a new master
+    // Start up a new master.  Wait until regionserver is completely down
+    // before starting new master because of hbase-4511.
+    while (hrsDeadThread.isAlive()) {
+      Threads.sleep(10);
+    }
     log("Starting up a new master");
     master = cluster.startMaster().getMaster();
     log("Waiting for master to be ready");