diff --git a/ifrs17/Import/ImportScopeCalculation.ipynb b/ifrs17/Import/ImportScopeCalculation.ipynb
index 59184a84..097661f1 100644
--- a/ifrs17/Import/ImportScopeCalculation.ipynb
+++ b/ifrs17/Import/ImportScopeCalculation.ipynb
@@ -549,7 +549,7 @@
                 "\n{",
                 "\n    private double[] NominalClaimsCashflow => GetStorage().GetClaims()",
                 "\n                            .Select(claim => GetStorage().GetValues(Identity.Id with {AocType = referenceAocStep.AocType, Novelty = referenceAocStep.Novelty}, claim, Identity.EstimateType, Identity.AccidentYear))",
-                "\n                            .Aggregate();",
+                "\n                            .AggregateDoubleArray();",
                 "\n                            ",
                 "\n    private double nonPerformanceRiskRate => GetStorage().GetNonPerformanceRiskRate(Identity.Id);",
                 "\n                            ",
@@ -566,7 +566,7 @@
                 "\n{",
                 "\n    double[] NominalCashflow.Values => GetStorage().GetClaims()",
                 "\n                                        .Select(claim => GetStorage().GetValues(Identity.Id with {AocType = referenceAocStep.AocType, Novelty = referenceAocStep.Novelty}, claim, Identity.EstimateType, Identity.AccidentYear))",
-                "\n                                        .Aggregate();",
+                "\n                                        .AggregateDoubleArray();",
                 "\n}"
             ],
             "metadata": {},
@@ -691,7 +691,7 @@
                 "\n                                            .Values",
                 "\n                                            .Select(aoc => GetScope<DiscountedCashflow>((Identity.Id with {AocType = aoc.AocType, Novelty = aoc.Novelty}, Identity.AmountType, Identity.EstimateType, Identity.Accidentyear)).Values)",
                 "\n                                            .Where(cf => cf.Count() > 0)",
-                "\n                                            .Aggregate();",
+                "\n                                            .AggregateDoubleArray();",
                 "\n    ",
                 "\n    double[] Values => Subtract(CurrentValues, PreviousValues);",
                 "\n}"
diff --git a/ifrs17/Test/AggregateDoubleArrayTest.ipynb b/ifrs17/Test/AggregateDoubleArrayTest.ipynb
new file mode 100644
index 00000000..6849995e
--- /dev/null
+++ b/ifrs17/Test/AggregateDoubleArrayTest.ipynb
@@ -0,0 +1,131 @@
+{
+    "metadata": {
+        "authors": [],
+        "kernelspec": {
+            "display_name": "Formula Framework",
+            "language": "C#",
+            "name": "C#"
+        },
+        "language_info": {
+            "file_extension": ".cs",
+            "mimetype": "text/plain",
+            "name": "C#"
+        }
+    },
+    "nbformat": 4,
+    "nbformat_minor": 5,
+    "cells": [
+        {
+            "cell_type": "code",
+            "source": [
+                "#!import \"../Utils/Extensions\"",
+                "\n#!import \"../Utils/TestHelper\""
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "public void CheckAggregateDoubleArray(double[][] arrayOfDoubleArrays, double[] bmAggregatedArray)",
+                "\n{",
+                "\n    var aggregatedArray = arrayOfDoubleArrays.AggregateDoubleArray();",
+                "\n    aggregatedArray.Should().BeEquivalentTo(bmAggregatedArray);",
+                "\n}"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "var array = new double [] [] {new[] {-100d,-50d }, new[] {-100d,-50d,-50d,-50d,0d,0d,0d,0d, 0d,0d,}, new[] {-100d,-50d,-50d,-50d,0d,0d,0d,0d, 0d,0d,}, new[] {-100d,-50d,-50d,-50d,0d,0d,0d,0d, 0d,0d,} };",
+                "\nCheckAggregateDoubleArray(array, new[] {-400d,-200d,-150d,-150d,0d,0d,0d,0d, 0d,0d,})"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "array = new double [] [] {null, new[] {-100d,-50d }};",
+                "\nCheckAggregateDoubleArray(array, new[] {-100d,-50d })"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "array = new double [] [] {new[] {-100d,-50d }, null};",
+                "\nCheckAggregateDoubleArray(array, new[] {-100d,-50d })"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "array = new double [] [] {Enumerable.Empty<double>().ToArray(), new[] {-100d,-50d }};",
+                "\nCheckAggregateDoubleArray(array, new[] {-100d,-50d })"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "array = new double [] [] {Enumerable.Empty<double>().ToArray(), Enumerable.Empty<double>().ToArray()};",
+                "\nCheckAggregateDoubleArray(array, Enumerable.Empty<double>().ToArray())"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "array = new double [] [] {new[] {-100d,-50d }};",
+                "\nCheckAggregateDoubleArray(array, new[] {-100d,-50d })"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "array = new double [] [] {Enumerable.Empty<double>().ToArray()};",
+                "\nCheckAggregateDoubleArray(array, Enumerable.Empty<double>().ToArray())"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "array = new double [] [] {null};",
+                "\nCheckAggregateDoubleArray(array, Enumerable.Empty<double>().ToArray())"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                ""
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        }
+    ]
+}
\ No newline at end of file
diff --git a/ifrs17/Test/Tests.ipynb b/ifrs17/Test/Tests.ipynb
index e2f0e955..ef37f404 100644
--- a/ifrs17/Test/Tests.ipynb
+++ b/ifrs17/Test/Tests.ipynb
@@ -41,6 +41,15 @@
             "metadata": {},
             "execution_count": 0,
             "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "#!eval-notebook \"AggregateDoubleArrayTest\""
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
         }
     ]
 }
\ No newline at end of file
diff --git a/ifrs17/Utils/Extensions.ipynb b/ifrs17/Utils/Extensions.ipynb
index a403aeff..9e335a22 100644
--- a/ifrs17/Utils/Extensions.ipynb
+++ b/ifrs17/Utils/Extensions.ipynb
@@ -36,6 +36,33 @@
             "execution_count": 0,
             "outputs": []
         },
+        {
+            "cell_type": "markdown",
+            "source": [
+                "# Loading external dependencies"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "#r \"nuget:morelinq\""
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "using static MoreLinq.Extensions.ZipLongestExtension;"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
         {
             "cell_type": "markdown",
             "source": [
@@ -96,7 +123,16 @@
         {
             "cell_type": "code",
             "source": [
-                "public static double[] Prune (this IEnumerable<double> source, double precision = Precision) => source.Reverse().SkipWhile(x => Math.Abs(x) < precision).Reverse().ToArray();"
+                "public static double[] Prune(this IEnumerable<double> source, double precision = Precision) => source.Reverse().SkipWhile(x => Math.Abs(x) < precision).Reverse().ToArray();"
+            ],
+            "metadata": {},
+            "execution_count": 0,
+            "outputs": []
+        },
+        {
+            "cell_type": "code",
+            "source": [
+                "public static double[] AggregateDoubleArray(this IEnumerable<IEnumerable<double>> source) => source.Where(x => x is not null).DefaultIfEmpty(Enumerable.Empty<double>()).Aggregate((x, y) => x.ZipLongest(y, (a, b) => a + b)).ToArray();"
             ],
             "metadata": {},
             "execution_count": 0,