diff --git a/packages/node_modules/pouchdb-abstract-mapreduce/src/index.js b/packages/node_modules/pouchdb-abstract-mapreduce/src/index.js
index ac00dd575c..0ec19ed37e 100644
--- a/packages/node_modules/pouchdb-abstract-mapreduce/src/index.js
+++ b/packages/node_modules/pouchdb-abstract-mapreduce/src/index.js
@@ -1,5 +1,4 @@
 import {
-  flatten,
   guardedConsole,
   nextTick,
   isRemote
@@ -486,7 +485,7 @@ function createAbstractMapReduce(localDocName, mapper, reducer, ddocValidator) {
         return Promise.all(docIds.map(function (docId) {
           return getDocsToPersist(docId, view, docIdsToChangesAndEmits);
         })).then(function (listOfDocsToPersist) {
-          var docsToPersist = flatten(listOfDocsToPersist);
+          var docsToPersist = listOfDocsToPersist.flat();
           lastSeqDoc.seq = seq;
           docsToPersist.push(lastSeqDoc);
           // write all docs in a single operation, update the seq once
@@ -853,7 +852,7 @@ function createAbstractMapReduce(localDocName, mapper, reducer, ddocValidator) {
         return fetchFromView(viewOpts);
       });
       const result = await Promise.all(fetchPromises);
-      const flattenedResult = flatten(result);
+      const flattenedResult = result.flat();
       return onMapResultsReady(flattenedResult);
     } else { // normal query, no 'keys'
       const viewOpts = {
diff --git a/packages/node_modules/pouchdb-adapter-http/src/index.js b/packages/node_modules/pouchdb-adapter-http/src/index.js
index 3f85051a5d..b4434bd17a 100644
--- a/packages/node_modules/pouchdb-adapter-http/src/index.js
+++ b/packages/node_modules/pouchdb-adapter-http/src/index.js
@@ -18,7 +18,6 @@ import {
   clone,
   parseUri,
   bulkGetShim,
-  flatten,
   nextTick
 } from 'pouchdb-utils';
 
@@ -377,7 +376,7 @@ function HttpPouch(opts, callback) {
           // err is impossible because shim returns a list of errs in that case
           results[batchNum] = res.results;
           if (++numDone === numBatches) {
-            callback(null, {results: flatten(results)});
+            callback(null, {results: results.flat()});
           }
         };
       }
diff --git a/packages/node_modules/pouchdb-replication/src/getDocs.js b/packages/node_modules/pouchdb-replication/src/getDocs.js
index 325c573e13..dfc4ab0d63 100644
--- a/packages/node_modules/pouchdb-replication/src/getDocs.js
+++ b/packages/node_modules/pouchdb-replication/src/getDocs.js
@@ -1,4 +1,4 @@
-import { clone, flatten, isRemote } from 'pouchdb-utils';
+import { clone, isRemote } from 'pouchdb-utils';
 
 function fileHasChanged(localDoc, remoteDoc, filename) {
   return !localDoc._attachments ||
@@ -112,7 +112,7 @@ function getDocs(src, target, diffs, state) {
       }))
 
       .then(function (results) {
-        resultDocs = resultDocs.concat(flatten(results).filter(Boolean));
+        resultDocs = resultDocs.concat(results.flat().filter(Boolean));
       });
     });
   }
diff --git a/packages/node_modules/pouchdb-utils/src/flatten.js b/packages/node_modules/pouchdb-utils/src/flatten.js
deleted file mode 100644
index 21b62afe6c..0000000000
--- a/packages/node_modules/pouchdb-utils/src/flatten.js
+++ /dev/null
@@ -1,9 +0,0 @@
-function flatten(arrs) {
-  var res = [];
-  for (var i = 0, len = arrs.length; i < len; i++) {
-    res = res.concat(arrs[i]);
-  }
-  return res;
-}
-
-export default flatten;
diff --git a/packages/node_modules/pouchdb-utils/src/index.js b/packages/node_modules/pouchdb-utils/src/index.js
index 53a2bfb557..19b4fe8a74 100644
--- a/packages/node_modules/pouchdb-utils/src/index.js
+++ b/packages/node_modules/pouchdb-utils/src/index.js
@@ -8,7 +8,6 @@ import guardedConsole from './guardedConsole';
 import defaultBackOff from './defaultBackOff';
 import explainError from './explainError';
 import filterChange from './filterChange';
-import flatten from './flatten';
 import functionName from './functionName';
 import hasLocalStorage from './env/hasLocalStorage';
 import invalidIdError from './invalidIdError';
@@ -35,7 +34,6 @@ export {
   defaultBackOff,
   explainError,
   filterChange,
-  flatten,
   functionName,
   guardedConsole,
   hasLocalStorage,