diff --git a/java/src/main/java/monasca/api/app/command/UpdateAlarmCommand.java b/java/src/main/java/monasca/api/app/command/UpdateAlarmCommand.java
index 1e9cb98d6..f485bf127 100644
--- a/java/src/main/java/monasca/api/app/command/UpdateAlarmCommand.java
+++ b/java/src/main/java/monasca/api/app/command/UpdateAlarmCommand.java
@@ -13,7 +13,6 @@
  */
 package monasca.api.app.command;
 
-import javax.annotation.Nullable;
 import javax.validation.constraints.NotNull;
 
 import monasca.common.model.alarm.AlarmState;
@@ -22,12 +21,14 @@ public class UpdateAlarmCommand {
 
   @NotNull
   public AlarmState state;
+  @NotNull
   public String lifecycleState;
+  @NotNull
   public String link;
 
   public UpdateAlarmCommand() {}
 
-  public UpdateAlarmCommand(AlarmState state, @Nullable String lifecycleState, @Nullable String link) {
+  public UpdateAlarmCommand(AlarmState state, String lifecycleState, String link) {
     this.state = state;
     this.lifecycleState = lifecycleState;
     this.link = link;
diff --git a/monasca_api/v2/reference/alarms.py b/monasca_api/v2/reference/alarms.py
index 4d0b2835f..6d69d2b21 100644
--- a/monasca_api/v2/reference/alarms.py
+++ b/monasca_api/v2/reference/alarms.py
@@ -57,12 +57,12 @@ class Alarms(alarms_api_v2.AlarmsV2API,
         if 'state' not in alarm or not alarm['state']:
             raise falcon.HTTPBadRequest('Bad request',
                                         "Field 'state' is required")
-
-        # Assume these fields are null if not provided
-        if 'lifecycle_state' not in alarm:
-            alarm['lifecycle_state'] = None
-        if 'link' not in alarm:
-            alarm['link'] = None
+        if 'lifecycle_state' not in alarm or not alarm['lifecycle_state']:
+            raise falcon.HTTPBadRequest('Bad Request',
+                                        "Field 'lifecycle_state' is required")
+        if 'link' not in alarm or not alarm['link']:
+            raise falcon.HTTPBadRequest('Bad Request',
+                                        "Field 'link' is required")
 
         self._alarm_update(tenant_id, alarm_id, alarm['state'],
                            alarm['lifecycle_state'], alarm['link'])