diff --git a/src/question_matrixdropdownbase.ts b/src/question_matrixdropdownbase.ts
index 92f421099c..bd81690fab 100644
--- a/src/question_matrixdropdownbase.ts
+++ b/src/question_matrixdropdownbase.ts
@@ -202,8 +202,12 @@ export class QuestionMatrixDropdownModelBase extends Question implements IMatrix
         }
         return result;
     }
+    protected onBeforeValueChanged(val: any) {
+    }
     protected onValueChanged() {
-        if (this.isRowChanging || !(this.generatedVisibleRows) || this.generatedVisibleRows.length == 0) return;
+        if (this.isRowChanging) return;
+        this.onBeforeValueChanged(this.value);
+        if(!(this.generatedVisibleRows) || this.generatedVisibleRows.length == 0) return;
         this.isRowChanging = true;
         var val = this.createNewValue(this.value);
         for (var i = 0; i < this.generatedVisibleRows.length; i++) {
diff --git a/src/question_matrixdynamic.ts b/src/question_matrixdynamic.ts
index e40c48a2be..9857046fbb 100644
--- a/src/question_matrixdynamic.ts
+++ b/src/question_matrixdynamic.ts
@@ -99,6 +99,14 @@ export class QuestionMatrixDynamicModel extends QuestionMatrixDropdownModelBase
     protected createMatrixRow(value: any): MatrixDynamicRowModel {
         return new MatrixDynamicRowModel(this.rowCounter ++, this, value);
     }
+    protected onBeforeValueChanged(val: any) {
+        var newRowCount = val && Array.isArray(val) ? val.length : 0;
+        if (newRowCount <= this.rowCount) return;
+        this.rowCountValue = newRowCount;
+        if (this.generatedVisibleRows) {
+            this.generatedVisibleRows = this.visibleRows;
+        }
+    }
     protected createNewValue(curValue: any): any {
         var result = curValue;
         if (!result) result = [];
diff --git a/tests/surveyquestiontests.ts b/tests/surveyquestiontests.ts
index 7909db4b4c..c71daef57e 100644
--- a/tests/surveyquestiontests.ts
+++ b/tests/surveyquestiontests.ts
@@ -459,6 +459,19 @@ QUnit.test("Matrixdynamic hasOther column", function (assert) {
     rows[0].cells[0].question.value = "other";
     assert.equal(question.hasErrors(), true, "Should set other value");
 });
+QUnit.test("Matrixdynamic adjust rowCount on setting the value", function (assert) {
+    var question = new QuestionMatrixDynamicModel("matrixDymanic");
+    question.rowCount = 0;
+    question.columns.push(new MatrixDropdownColumn("column1"));
+    question.columns.push(new MatrixDropdownColumn("column2"));
+    question.value = [{}, { 'column1': 2 }, {}];
+    assert.equal(question.rowCount, 3, "It should be 3 rowCount");
+    var rows = question.visibleRows;
+    question.value = [{}, { 'column1': 2 }, {}, {}];
+    assert.equal(question.rowCount, 4, "It should be 4 rowCount");
+    question.value = [{ 'column1': 2 }];
+    assert.equal(question.rowCount, 4, "Keep row count equals 4");
+});
 QUnit.test("Matrixdropdown different cell types", function (assert) {
     var question = new QuestionMatrixDropdownModel("matrixDropdown");