diff --git a/src/index.js b/src/index.js
index c5e349d..1b1536f 100644
--- a/src/index.js
+++ b/src/index.js
@@ -2,7 +2,7 @@ import events from 'events';
 import createClient from './helpers/es_client';
 import indexTimestamp from './helpers/index_timestamp';
 import logger from './helpers/logger';
-import { defaultSettings } from './helpers/constants';
+import constants from './helpers/constants';
 import Job from './job.js';
 import Worker from './worker.js';
 import omit from 'lodash.omit';
@@ -16,14 +16,14 @@ export default class Esqueue extends events.EventEmitter {
     super();
     this.index = index;
     this.settings = Object.assign({
-      interval: defaultSettings.DEFAULT_SETTING_INTERVAL,
-      timeout: defaultSettings.DEFAULT_SETTING_TIMEOUT,
-      doctype: defaultSettings.DEFAULT_SETTING_DOCTYPE,
+      interval: constants.DEFAULT_SETTING_INTERVAL,
+      timeout: constants.DEFAULT_SETTING_TIMEOUT,
+      doctype: constants.DEFAULT_SETTING_DOCTYPE,
     }, omit(options, [ 'client' ]));
     this.client = createClient(options.client || {});
 
     this._workers = [];
-    this._initTasks().catch((err) => this.emit('error', err));
+    this._initTasks().catch((err) => this.emit(constants.EVENT_QUEUE_ERROR, err));
   }
 
   _initTasks() {
diff --git a/src/job.js b/src/job.js
index 86f6318..dd501e5 100644
--- a/src/job.js
+++ b/src/job.js
@@ -56,11 +56,11 @@ export default class Job extends events.EventEmitter {
         version: doc._version,
       };
       this.debug(`Job created in index ${this.index}`);
-      this.emit('created', this.document);
+      this.emit(contstants.EVENT_JOB_CREATED, this.document);
     })
     .catch((err) => {
       this.debug('Job creation failed', err);
-      this.emit('error', err);
+      this.emit(contstants.EVENT_JOB_ERROR, err);
     });
   }
 
diff --git a/src/worker.js b/src/worker.js
index 508836e..92e9b76 100644
--- a/src/worker.js
+++ b/src/worker.js
@@ -69,7 +69,7 @@ export default class Job extends events.EventEmitter {
     .catch((err) => {
       if (err.statusCode === 409) return true;
       this.debug(`_claimJob failed on job ${job._id}`, err);
-      this.emit('claim_error', err);
+      this.emit(constants.EVENT_WORKER_JOB_CLAIM_ERROR, err);
       return false;
     });
   }
@@ -97,8 +97,8 @@ export default class Job extends events.EventEmitter {
     .then(() => true)
     .catch((err) => {
       if (err.statusCode === 409) return true;
-      this.debug(`_failJob failed on job ${job._id}`, err);
-      this.emit('fail_error', err);
+      this.debug(`_failJob failed to update job ${job._id}`, err);
+      this.emit(constants.EVENT_WORKER_FAIL_UPDATE_ERROR, err);
       return false;
     });
   }
@@ -170,7 +170,7 @@ export default class Job extends events.EventEmitter {
       .catch((err) => {
         if (err.statusCode === 409) return false;
         this.debug(`Failure saving job output ${job._id}`, err);
-        this.emit('job_error', err);
+        this.emit(constants.EVENT_WORKER_JOB_UPDATE_ERROR, err);
       });
     }, (jobErr) => {
       if (!jobErr) {
@@ -182,12 +182,12 @@ export default class Job extends events.EventEmitter {
       // job execution failed
       if (jobErr.type === 'WorkerTimeoutError') {
         this.debug(`Timeout on job ${job._id}`);
-        this.emit('job_timeout', jobErr);
+        this.emit(constants.EVENT_WORKER_JOB_TIMEOUT_ERROR, jobErr);
         return;
       }
 
       this.debug(`Failure occurred on job ${job._id}`, jobErr);
-      this.emit('job_error', jobErr);
+      this.emit(constants.EVENT_WORKER_JOB_EXECUTION_ERROR, jobErr);
       return this._failJob(job, (jobErr.toString) ? jobErr.toString() : false);
     });
   }
@@ -235,7 +235,6 @@ export default class Job extends events.EventEmitter {
     .then(() => this._startJobPolling())
     .catch((err) => {
       this.debug('Error claiming jobs', err);
-      this.emit('error', err);
       this._startJobPolling();
     });
   }
@@ -289,7 +288,7 @@ export default class Job extends events.EventEmitter {
       if (err.status === 404) return [];
 
       this.debug('job querying failed', err);
-      this.emit('error', err);
+      this.emit(constants.EVENT_WORKER_JOB_SEARCH_ERROR, err);
     });
   }
 }
\ No newline at end of file