diff --git a/src/main/java/org/elasticsearch/alerts/actions/AlertActionEntry.java b/src/main/java/org/elasticsearch/alerts/actions/AlertActionEntry.java
index ca9ae8938ff..43b4b2bb31a 100644
--- a/src/main/java/org/elasticsearch/alerts/actions/AlertActionEntry.java
+++ b/src/main/java/org/elasticsearch/alerts/actions/AlertActionEntry.java
@@ -216,7 +216,7 @@ public class AlertActionEntry implements ToXContent{
         historyEntry.field(AlertActionState.FIELD_NAME, entryState.toString());
 
         if (errorMsg != null) {
-            historyEntry.field("errorMsg", errorMsg);
+            historyEntry.field("error_msg", errorMsg);
         }
         historyEntry.endObject();
 
diff --git a/src/main/java/org/elasticsearch/alerts/actions/AlertActionManager.java b/src/main/java/org/elasticsearch/alerts/actions/AlertActionManager.java
index a61e80d0253..0a0a3620790 100644
--- a/src/main/java/org/elasticsearch/alerts/actions/AlertActionManager.java
+++ b/src/main/java/org/elasticsearch/alerts/actions/AlertActionManager.java
@@ -45,7 +45,7 @@ public class AlertActionManager extends AbstractComponent {
     public static final String TRIGGERED_FIELD = "triggered";
     public static final String FIRE_TIME_FIELD = "fire_time";
     public static final String SCHEDULED_FIRE_TIME_FIELD = "scheduled_fire_time";
-    public static final String ERROR_MESSAGE = "errorMsg";
+    public static final String ERROR_MESSAGE = "error_msg";
     public static final String TRIGGER_FIELD = "trigger";
     public static final String REQUEST = "request";
     public static final String RESPONSE = "response_binary";