diff --git a/README.md b/README.md
index a5e3f68..9b56453 100644
--- a/README.md
+++ b/README.md
@@ -64,7 +64,8 @@ If multiple objects are provided as arguments, the contents are stringified.
 - `messageType` [`_doc`] the type (path segment after the index path) under which the messages are stored under the index.
 - `transformer` [see below] a transformer function to transform logged data into a different message structure.
 - `ensureMappingTemplate` [`true`] If set to `true`, the given `mappingTemplate` is checked/ uploaded to ES when the module is sending the fist log message to make sure the log messages are mapped in a sensible manner.
-- `mappingTemplate` [see file `index-template-mapping.json` file] the mapping template to be ensured as parsed JSON.
+- `mappingTemplate` [see file `index-template-mapping-es-gte-7.json` or `index-template-mapping-es-lte-6.json`] the mapping template to be ensured as parsed JSON.
+- `elasticsearchVersion` [`7`] Elasticsearch version you are using. This helps decide the default mapping template that will be used when `ensureMappingTemplate` is `true` and `mappingTemplate` is `undefined`
 - `flushInterval` [`2000`] distance between bulk writes in ms.
 - `client` An [elasticsearch client](https://www.npmjs.com/package/@elastic/elasticsearch) instance. If given, all following options are ignored.
 - `clientOpts` An object hash passed to the ES client. See [its docs](https://www.elastic.co/guide/en/elasticsearch/client/javascript-api/current/client-configuration.html) for supported options.
diff --git a/bulk_writer.js b/bulk_writer.js
index eaf5170..1399d95 100644
--- a/bulk_writer.js
+++ b/bulk_writer.js
@@ -183,34 +183,40 @@ BulkWriter.prototype.checkEsConnection = function checkEsConnection() {
       debug('checking for ES connection');
       thiz.client.cluster.health({
         timeout: '5s',
-        wait_for_nodes: '1',
+        wait_for_nodes: '>=1',
         wait_for_status: 'yellow'
       })
         .then(
-        (res) => {
-          thiz.esConnection = true;
-          // Ensure mapping template is existing if desired
-          if (thiz.options.ensureMappingTemplate) {
-            thiz.ensureMappingTemplate(fulfill, reject);
-          } else {
-            fulfill(true);
-          }
-          if (thiz.options.buffering === true) {
-            debug('starting bulk writer');
-            thiz.running = true;
-            thiz.tick();
-          }
-        },
-        (err) => {
-          debug('re-checking for connection to ES');
-          if (operation.retry(err)) {
-            return;
+          (res) => {
+            thiz.esConnection = true;
+            const start = () => {
+              if (thiz.options.buffering === true) {
+                debug('starting bulk writer');
+                thiz.running = true;
+                thiz.tick();
+              }
+            };
+            // Ensure mapping template is existing if desired
+            if (thiz.options.ensureMappingTemplate) {
+              thiz.ensureMappingTemplate((res1) => {
+                fulfill(res1);
+                start();
+              }, reject);
+            } else {
+              fulfill(true);
+              start();
+            }
+          },
+          (err) => {
+            debug('re-checking for connection to ES');
+            if (operation.retry(err)) {
+              return;
+            }
+            thiz.esConnection = false;
+            debug('cannot connect to ES');
+            reject(new Error('Cannot connect to ES'));
           }
-          thiz.esConnection = false;
-          debug('cannot connect to ES');
-          reject(new Error('Cannot connect to ES'));
-        }
-      );
+        );
     });
   });
 };
@@ -227,8 +233,11 @@ BulkWriter.prototype.ensureMappingTemplate = function ensureMappingTemplate(
   // eslint-disable-next-line prefer-destructuring
   let mappingTemplate = thiz.options.mappingTemplate;
   if (mappingTemplate === null || typeof mappingTemplate === 'undefined') {
+    // es version 6 and below will use 'index-template-mapping-es-lte-6.json'
+    // 7 and above will use 'index-template-mapping-es-gte-7.json'
+    const esVersion = Number(thiz.options.elasticsearchVersion) >= 7 ? 'gte-7' : 'lte-6';
     const rawdata = fs.readFileSync(
-      path.join(__dirname, 'index-template-mapping.json')
+      path.join(__dirname, 'index-template-mapping-es-' + esVersion + '.json')
     );
     mappingTemplate = JSON.parse(rawdata);
     mappingTemplate.index_patterns = indexPrefix + '-*';
diff --git a/index-template-mapping-es-gte-7.json b/index-template-mapping-es-gte-7.json
new file mode 100644
index 0000000..5c86a60
--- /dev/null
+++ b/index-template-mapping-es-gte-7.json
@@ -0,0 +1,22 @@
+{
+  "index_patterns": ["logs-*"],
+  "settings": {
+    "number_of_shards": 1,
+    "number_of_replicas": 0,
+    "index": {
+      "refresh_interval": "5s"
+    }
+  },
+  "mappings": {
+    "properties": {
+      "@timestamp": { "type": "date" },
+      "@version": { "type": "keyword" },
+      "message": { "type": "text" },
+      "severity": { "type": "keyword" },
+      "fields": {
+        "dynamic": true,
+        "properties": { }
+      }
+    }
+  }
+}
diff --git a/index-template-mapping-es-lte-6.json b/index-template-mapping-es-lte-6.json
new file mode 100644
index 0000000..37c390c
--- /dev/null
+++ b/index-template-mapping-es-lte-6.json
@@ -0,0 +1,36 @@
+{
+  "index_patterns": [
+    "logs-*"
+  ],
+  "settings": {
+    "number_of_shards": 1,
+    "number_of_replicas": 0,
+    "index": {
+      "refresh_interval": "5s"
+    }
+  },
+  "mappings": {
+    "_doc": {
+      "properties": {
+        "@timestamp": {
+          "type": "date"
+        },
+        "@version": {
+          "type": "keyword"
+        },
+        "message": {
+          "type": "text",
+          "index": true
+        },
+        "severity": {
+          "type": "keyword",
+          "index": true
+        },
+        "fields": {
+          "dynamic": true,
+          "properties": {}
+        }
+      }
+    }
+  }
+}
diff --git a/index-template-mapping.json b/index-template-mapping.json
deleted file mode 100644
index 1b069be..0000000
--- a/index-template-mapping.json
+++ /dev/null
@@ -1,37 +0,0 @@
-{
-  "index_patterns": [
-    "logs-*"
-  ],
-  "settings": {
-    "number_of_shards": 1,
-    "number_of_replicas": 0,
-    "index": {
-      "refresh_interval": "5s"
-    }
-  },
-  "mappings": {
-    "_source": {
-      "enabled": true
-    },
-    "properties": {
-      "@timestamp": {
-        "type": "date"
-      },
-      "@version": {
-        "type": "keyword"
-      },
-      "message": {
-        "type": "text",
-        "index": true
-      },
-      "severity": {
-        "type": "keyword",
-        "index": true
-      },
-      "fields": {
-        "dynamic": true,
-        "properties": {}
-      }
-    }
-  }
-}
diff --git a/index.d.ts b/index.d.ts
index ed007a0..3731b06 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -22,6 +22,7 @@ export interface ElasticsearchTransportOptions extends TransportStream.Transport
   transformer?: Transformer;
   mappingTemplate?: { [key: string]: any };
   ensureMappingTemplate?: boolean;
+  elasticsearchVersion?: number;
   flushInterval?: number;
   waitForActiveShards?: number | 'all';
   handleExceptions?: boolean;
diff --git a/index.js b/index.js
index e8ea45c..6efdd4c 100644
--- a/index.js
+++ b/index.js
@@ -40,6 +40,7 @@ class ElasticsearchTransport extends Transport {
       messageType: '_doc',
       transformer: defaultTransformer,
       ensureMappingTemplate: true,
+      elasticsearchVersion: 7,
       flushInterval: 2000,
       waitForActiveShards: 1,
       handleExceptions: false,
@@ -79,6 +80,7 @@ class ElasticsearchTransport extends Transport {
       indexPrefix: opts.indexPrefix,
       buffering: opts.buffering,
       bufferLimit: opts.buffering ? opts.bufferLimit : 0,
+      elasticsearchVersion: opts.elasticsearchVersion,
     };
 
     this.bulkWriter = new BulkWriter(this, this.client, bulkWriteropts);
diff --git a/test/test.js b/test/test.js
index 0810bf1..128fe93 100644
--- a/test/test.js
+++ b/test/test.js
@@ -1,6 +1,7 @@
 const fs = require('fs');
 const should = require('should');
 const winston = require('winston');
+const http = require('http');
 
 require('../index');
 const defaultTransformer = require('../transformer');
@@ -23,12 +24,23 @@ function NullLogger(config) {
   this.close = (msg) => {};
 }
 
+process.on('unhandledRejection', (error) => {
+  console.error(error);
+  process.exit(1);
+});
+process.on('uncaughtException', (error) => {
+  console.error(error);
+  process.exit(1);
+});
+
+let elasticsearchVersion = 7;
 function createLogger(buffering) {
   return winston.createLogger({
     transports: [
       new winston.transports.Elasticsearch({
         flushInterval: 1,
         buffering,
+        elasticsearchVersion,
         clientOpts: {
           log: NullLogger,
           node: 'http://localhost:9200'
@@ -38,6 +50,25 @@ function createLogger(buffering) {
   });
 }
 
+before(() => {
+  return new Promise((resolve) => {
+    // get ES version being used
+    http.get('http://localhost:9200', (res) => {
+      res.setEncoding('utf8');
+      let body = '';
+      res.on('data', (data) => {
+        body += data;
+      });
+      res.on('error', () => { resolve(); });
+      res.on('end', () => {
+        body = JSON.parse(body);
+        elasticsearchVersion = parseInt(body.version.number.split('.')[0], 10) || 7;
+        resolve();
+      });
+    });
+  });
+});
+
 describe('the default transformer', () => {
   it('should transform log data from winston into a logstash like structure', (done) => {
     const transformed = defaultTransformer({