diff --git a/src/datasource-zabbix/dataProcessor.js b/src/datasource-zabbix/dataProcessor.js
index 2d29bd4..1c5942e 100644
--- a/src/datasource-zabbix/dataProcessor.js
+++ b/src/datasource-zabbix/dataProcessor.js
@@ -107,7 +107,7 @@ function groupByWrapper(interval, groupFunc, datapoints) {
 
 function aggregateByWrapper(interval, aggregateFunc, datapoints) {
   // Flatten all points in frame and then just use groupBy()
-  const flattenedPoints = _.flatten(datapoints, true);
+  const flattenedPoints = ts.flattenDatapoints(datapoints);
   // groupBy_perf works with sorted series only
   const sortedPoints = ts.sortByTime(flattenedPoints);
   let groupByCallback = aggregationFunctions[aggregateFunc];
@@ -115,14 +115,14 @@ function aggregateByWrapper(interval, aggregateFunc, datapoints) {
 }
 
 function aggregateWrapper(groupByCallback, interval, datapoints) {
-  var flattenedPoints = _.flatten(datapoints, true);
+  var flattenedPoints = ts.flattenDatapoints(datapoints);
   // groupBy_perf works with sorted series only
   const sortedPoints = ts.sortByTime(flattenedPoints);
   return groupBy(sortedPoints, interval, groupByCallback);
 }
 
 function percentil(interval, n, datapoints) {
-  var flattenedPoints = _.flatten(datapoints, true);
+  var flattenedPoints = ts.flattenDatapoints(datapoints);
   var groupByCallback = _.partial(PERCENTIL, n);
   return groupBy(flattenedPoints, interval, groupByCallback);
 }
diff --git a/src/datasource-zabbix/specs/utils.spec.js b/src/datasource-zabbix/specs/utils.spec.js
index d460baa..3367f1f 100644
--- a/src/datasource-zabbix/specs/utils.spec.js
+++ b/src/datasource-zabbix/specs/utils.spec.js
@@ -138,4 +138,31 @@ describe('Utils', () => {
       done();
     });
   });
+
+  describe('getArrayDepth()', () => {
+    it('should calculate proper array depth', () => {
+      const test_cases = [
+        {
+          array: [],
+          depth: 1
+        },
+        {
+          array: [1, 2, 3],
+          depth: 1
+        },
+        {
+          array: [[1, 2], [3, 4]],
+          depth: 2
+        },
+        {
+          array: [ [[1, 2], [3, 4]], [[1, 2], [3, 4]] ],
+          depth: 3
+        },
+      ];
+
+      for (const test_case of test_cases) {
+        expect(utils.getArrayDepth(test_case.array)).toBe(test_case.depth);
+      }
+    });
+  });
 });
diff --git a/src/datasource-zabbix/timeseries.js b/src/datasource-zabbix/timeseries.js
index 9390c3f..1e23114 100644
--- a/src/datasource-zabbix/timeseries.js
+++ b/src/datasource-zabbix/timeseries.js
@@ -478,6 +478,15 @@ function findNearestLeft(series, pointIndex) {
   return null;
 }
 
+function flattenDatapoints(datapoints) {
+  const depth = utils.getArrayDepth(datapoints);
+  if (depth <= 2) {
+    // Don't process if datapoints already flattened
+    return datapoints;
+  }
+  return _.flatten(datapoints);
+}
+
 ////////////
 // Export //
 ////////////
@@ -501,7 +510,8 @@ const exportedFunctions = {
   MAX,
   MEDIAN,
   PERCENTIL,
-  sortByTime
+  sortByTime,
+  flattenDatapoints,
 };
 
 export default exportedFunctions;
diff --git a/src/datasource-zabbix/utils.js b/src/datasource-zabbix/utils.js
index ab6639e..517569f 100644
--- a/src/datasource-zabbix/utils.js
+++ b/src/datasource-zabbix/utils.js
@@ -265,6 +265,17 @@ export function compactQuery(query) {
   return query.replace(/\s+/g, ' ').trim();
 }
 
+export function getArrayDepth(a, level = 0) {
+  if (a.length === 0) {
+    return 1;
+  }
+  const elem = a[0];
+  if (_.isArray(elem)) {
+    return getArrayDepth(elem, level + 1);
+  }
+  return level + 1;
+}
+
 // Fix for backward compatibility with lodash 2.4
 if (!_.includes) {
   _.includes = _.contains;