diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/Times.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/Times.java
index f113bd31c4a..3c415586274 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/Times.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/util/Times.java
@@ -105,6 +105,9 @@ public static String formatISO8601(long ts) {
    */
   public static long parseISO8601ToLocalTimeInMillis(String isoString)
       throws ParseException {
+    if (isoString == null) {
+      throw new ParseException("Invalid input.", -1);
+    }
     return isoFormat.get().parse(isoString).getTime();
   }
 }
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/RMServerUtils.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/RMServerUtils.java
index a0cdf6889e3..74898caecbd 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/RMServerUtils.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/RMServerUtils.java
@@ -507,7 +507,8 @@ public static Map<ApplicationTimeoutType, Long> validateISO8601AndConvertToLocal
         } catch (ParseException ex) {
           String message =
               "Expire time is not in ISO8601 format. ISO8601 supported "
-                  + "format is yyyy-MM-dd'T'HH:mm:ss.SSSZ";
+                  + "format is yyyy-MM-dd'T'HH:mm:ss.SSSZ. Configured "
+                  + "timeout value is " + timeout.getValue();
           throw new YarnException(message, ex);
         }
         if (expireTime < currentTimeMillis) {
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
index a46fb813f0b..bd0602b5eac 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/main/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/RMWebServices.java
@@ -2434,7 +2434,7 @@ public ReservationListResponse run() throws IOException,
   }
 
   @GET
-  @Path("/apps/{appid}/timeout/{type}")
+  @Path("/apps/{appid}/timeouts/{type}")
   @Produces({ MediaType.APPLICATION_JSON + "; " + JettyUtils.UTF_8,
       MediaType.APPLICATION_XML + "; " + JettyUtils.UTF_8 })
   public AppTimeoutInfo getAppTimeout(@Context HttpServletRequest hsr,
@@ -2571,10 +2571,10 @@ public Response updateApplicationTimeout(AppTimeoutInfo appTimeout,
   private Response updateApplicationTimeouts(final RMApp app,
       UserGroupInformation callerUGI, final AppTimeoutInfo appTimeout)
       throws IOException, InterruptedException {
-
-    if (appTimeout.getTimeoutType() == null) {
-      return Response.status(Status.BAD_REQUEST).entity("Timeout type is null.")
-          .build();
+    if (appTimeout.getTimeoutType() == null
+        || appTimeout.getExpireTime() == null) {
+      return Response.status(Status.BAD_REQUEST)
+          .entity("Timeout type or ExpiryTime is null.").build();
     }
 
     String userName = callerUGI.getUserName();
diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesAppsModification.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesAppsModification.java
index 64584715d22..5d99e0d169d 100644
--- a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesAppsModification.java
+++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/webapp/TestRMWebServicesAppsModification.java
@@ -1328,19 +1328,11 @@ public void testUpdateAppTimeout() throws Exception {
               ApplicationTimeoutType.LIFETIME, "UNLIMITED", -1);
         }
 
-        AppTimeoutInfo timeoutUpdate = new AppTimeoutInfo();
         long timeOutFromNow = 60;
         String expireTime = Times
             .formatISO8601(System.currentTimeMillis() + timeOutFromNow * 1000);
-        timeoutUpdate.setTimeoutType(ApplicationTimeoutType.LIFETIME);
-        timeoutUpdate.setExpiryTime(expireTime);
-
-        Object entity;
-        if (contentType.equals(MediaType.APPLICATION_JSON_TYPE)) {
-          entity = appTimeoutToJSON(timeoutUpdate);
-        } else {
-          entity = timeoutUpdate;
-        }
+        Object entity = getAppTimeoutInfoEntity(ApplicationTimeoutType.LIFETIME,
+            contentType, expireTime);
         response = this
             .constructWebResource("apps", app.getApplicationId().toString(),
                 "timeout")
@@ -1361,10 +1353,20 @@ public void testUpdateAppTimeout() throws Exception {
               expireTime, timeOutFromNow);
         }
 
+        // verify for negative cases
+        entity = getAppTimeoutInfoEntity(null,
+            contentType, null);
+        response = this
+            .constructWebResource("apps", app.getApplicationId().toString(),
+                "timeout")
+            .entity(entity, contentType).accept(mediaType)
+            .put(ClientResponse.class);
+        assertResponseStatusCode(Status.BAD_REQUEST, response.getStatusInfo());
+
         // invoke get
         response =
             this.constructWebResource("apps", app.getApplicationId().toString(),
-                "timeout", ApplicationTimeoutType.LIFETIME.toString())
+                "timeouts", ApplicationTimeoutType.LIFETIME.toString())
                 .accept(mediaType).get(ClientResponse.class);
         assertResponseStatusCode(Status.OK, response.getStatusInfo());
         if (mediaType.contains(MediaType.APPLICATION_JSON)) {
@@ -1376,6 +1378,21 @@ public void testUpdateAppTimeout() throws Exception {
     rm.stop();
   }
 
+  private Object getAppTimeoutInfoEntity(ApplicationTimeoutType type,
+      MediaType contentType, String expireTime) throws Exception {
+    AppTimeoutInfo timeoutUpdate = new AppTimeoutInfo();
+    timeoutUpdate.setTimeoutType(type);
+    timeoutUpdate.setExpiryTime(expireTime);
+
+    Object entity;
+    if (contentType.equals(MediaType.APPLICATION_JSON_TYPE)) {
+      entity = appTimeoutToJSON(timeoutUpdate);
+    } else {
+      entity = timeoutUpdate;
+    }
+    return entity;
+  }
+
   protected static void verifyAppTimeoutJson(ClientResponse response,
       ApplicationTimeoutType type, String expireTime, long timeOutFromNow)
       throws JSONException {