diff --git a/src/PhpSpreadsheet/Calculation/MathTrig.php b/src/PhpSpreadsheet/Calculation/MathTrig.php
index bdc1e026..99a52e97 100644
--- a/src/PhpSpreadsheet/Calculation/MathTrig.php
+++ b/src/PhpSpreadsheet/Calculation/MathTrig.php
@@ -1088,7 +1088,7 @@ class MathTrig
                 list(, $row, $column) = explode('.', $index);
                 if ($cellReference->getWorksheet()->cellExists($column . $row)) {
                     //take this cell out if it contains the SUBTOTAL formula
-                    return strpos(strtoupper($cellReference->getWorksheet()->getCell($column . $row)->getValue()), '=SUBTOTAL(') === false;
+                    return !preg_match('/=.*\b(SUBTOTAL)\s*\(/', strtoupper($cellReference->getWorksheet()->getCell($column . $row)->getValue()));
                 }
                 return true;
             },
diff --git a/tests/PhpSpreadsheetTests/Calculation/MathTrigTest.php b/tests/PhpSpreadsheetTests/Calculation/MathTrigTest.php
index 4d6048f1..eda750af 100644
--- a/tests/PhpSpreadsheetTests/Calculation/MathTrigTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/MathTrigTest.php
@@ -547,11 +547,11 @@ class MathTrigTest extends TestCase
     }
 
     /**
-     * @dataProvider providerSUBTOTALHIDDEN
+     * @dataProvider providerHiddenSUBTOTAL
      *
      * @param mixed $expectedResult
      */
-    public function testSUBTOTALHIDDEN($expectedResult, ...$args)
+    public function testHiddenSUBTOTAL($expectedResult, ...$args)
     {
         $generator = \PhpOffice\PhpSpreadsheetTests\Calculation\MathTrigTest::rowVisibility();
         $rowDimension = $this->getMockBuilder(RowDimension::class)
@@ -596,8 +596,47 @@ class MathTrigTest extends TestCase
         self::assertEquals($expectedResult, $result, null, 1E-12);
     }
 
-    public function providerSUBTOTALHIDDEN()
+    public function providerHiddenSUBTOTAL()
     {
         return require 'data/Calculation/MathTrig/SUBTOTALHIDDEN.php';
     }
+
+    /**
+     * @dataProvider providerNestedSUBTOTAL
+     *
+     * @param mixed $expectedResult
+     */
+    public function testNestedSUBTOTAL($expectedResult, ...$args)
+    {
+        $cell = $this->getMockBuilder(Cell::class)
+            ->setMethods(['getValue'])
+            ->disableOriginalConstructor()
+            ->getMock();
+        $cell->method('getValue')
+            ->willReturn(null);
+        $worksheet = $this->getMockBuilder(Worksheet::class)
+            ->setMethods(['cellExists', 'getCell'])
+            ->disableOriginalConstructor()
+            ->getMock();
+        $worksheet->method('cellExists')
+            ->willReturn(true);
+        $worksheet->method('getCell')
+            ->willReturn($cell);
+        $cellReference = $this->getMockBuilder(Cell::class)
+            ->setMethods(['getWorksheet'])
+            ->disableOriginalConstructor()
+            ->getMock();
+        $cellReference->method('getWorksheet')
+            ->willReturn($worksheet);
+
+        array_push($args, $cellReference);
+        $result = MathTrig::SUBTOTAL(...$args);
+        self::assertEquals($expectedResult, $result, null, 1E-12);
+    }
+
+    public function providerNestedSUBTOTAL()
+    {
+        return require 'data/Calculation/MathTrig/SUBTOTALNESTED.php';
+    }
+
 }
diff --git a/tests/data/Calculation/MathTrig/SUBTOTALNESTED.php b/tests/data/Calculation/MathTrig/SUBTOTALNESTED.php
new file mode 100644
index 00000000..20a8e170
--- /dev/null
+++ b/tests/data/Calculation/MathTrig/SUBTOTALNESTED.php
@@ -0,0 +1,16 @@
+<?php
+
+$baseTestData = [
+    1 => ['A' => 1],
+    2 => ['A' => 1],
+    3 => ['A' => '=SUBTOTAL(1, A1:A2)'],
+    4 => ['A' => '=ROMAN(SUBTOTAL(1, A1:A2))']
+];
+
+return [
+    [
+        2,
+        2,
+        $baseTestData,
+    ],
+];