diff --git a/packages/CodingStyle/tests/Rector/ClassConst/VarConstantCommentRector/Fixture/union_nested_and_single_level_array_scalars.php.inc b/packages/CodingStyle/tests/Rector/ClassConst/VarConstantCommentRector/Fixture/union_nested_and_single_level_array_scalars.php.inc
new file mode 100644
index 00000000000..73033f68f1d
--- /dev/null
+++ b/packages/CodingStyle/tests/Rector/ClassConst/VarConstantCommentRector/Fixture/union_nested_and_single_level_array_scalars.php.inc
@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\CodingStyle\Tests\Rector\ClassConst\VarConstantCommentRector;
+
+class UnionNestedAndSingleLevelArrayScalars
+{
+    /**
+     * @var mixed[]
+     */
+    public const ARRAY_CONST = [
+        'key2' => ['value2', 1234],
+        1 => null,
+    ];
+}
+
+?>
+-----
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\CodingStyle\Tests\Rector\ClassConst\VarConstantCommentRector;
+
+class UnionNestedAndSingleLevelArrayScalars
+{
+    /**
+     * @var int[][]|string[][]|null[]
+     */
+    public const ARRAY_CONST = [
+        'key2' => ['value2', 1234],
+        1 => null,
+    ];
+}
+
+?>
diff --git a/packages/CodingStyle/tests/Rector/ClassConst/VarConstantCommentRector/Fixture/union_nested_array_scalars.php.inc b/packages/CodingStyle/tests/Rector/ClassConst/VarConstantCommentRector/Fixture/union_nested_array_scalars.php.inc
new file mode 100644
index 00000000000..a7e1f5b7fc8
--- /dev/null
+++ b/packages/CodingStyle/tests/Rector/ClassConst/VarConstantCommentRector/Fixture/union_nested_array_scalars.php.inc
@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\CodingStyle\Tests\Rector\ClassConst\VarConstantCommentRector;
+
+class UnionNestedArrayScalars
+{
+    /**
+     * @var mixed[]
+     */
+    public const STRING_ONLY = [
+        'key' => 'value',
+    ];
+
+    /**
+     * @var mixed[]
+     */
+    public const NESTED_STRING_INT = [
+        'key2' => ['value2', 1234],
+    ];
+
+    /**
+     * @var mixed[]
+     */
+    public const STRING_AND_NULL = [
+        'key' => 'value',
+        1 => null,
+    ];
+}
+
+?>
+-----
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\CodingStyle\Tests\Rector\ClassConst\VarConstantCommentRector;
+
+class UnionNestedArrayScalars
+{
+    /**
+     * @var string[]
+     */
+    public const STRING_ONLY = [
+        'key' => 'value',
+    ];
+
+    /**
+     * @var int[][]|string[][]
+     */
+    public const NESTED_STRING_INT = [
+        'key2' => ['value2', 1234],
+    ];
+
+    /**
+     * @var string[]|null[]
+     */
+    public const STRING_AND_NULL = [
+        'key' => 'value',
+        1 => null,
+    ];
+}
+
+?>
diff --git a/packages/NodeTypeResolver/src/StaticTypeMapper.php b/packages/NodeTypeResolver/src/StaticTypeMapper.php
index 5dd06c67a4f..c074928303b 100644
--- a/packages/NodeTypeResolver/src/StaticTypeMapper.php
+++ b/packages/NodeTypeResolver/src/StaticTypeMapper.php
@@ -114,6 +114,11 @@ final class StaticTypeMapper
 
         if ($phpStanType instanceof ArrayType || $phpStanType instanceof IterableType) {
             $itemTypeNode = $this->mapPHPStanTypeToPHPStanPhpDocTypeNode($phpStanType->getItemType());
+
+            if ($itemTypeNode instanceof UnionTypeNode) {
+                return $this->convertUnionArrayTypeNodesToArrayTypeOfUnionTypeNodes($itemTypeNode);
+            }
+
             return new ArrayTypeNode($itemTypeNode);
         }
 
@@ -868,4 +873,24 @@ final class StaticTypeMapper
 
         return is_a($secondType->getClassName(), $firstType->getClassName(), true);
     }
+
+    private function convertUnionArrayTypeNodesToArrayTypeOfUnionTypeNodes(
+        UnionTypeNode $unionTypeNode
+    ): AttributeAwareUnionTypeNode {
+        $unionedArrayType = [];
+        foreach ($unionTypeNode->types as $unionedType) {
+            if ($unionedType instanceof UnionTypeNode) {
+                foreach ($unionedType->types as $key => $subUnionedType) {
+                    $unionedType->types[$key] = new ArrayTypeNode($subUnionedType);
+                }
+
+                $unionedArrayType[] = $unionedType;
+                continue;
+            }
+
+            $unionedArrayType[] = new ArrayTypeNode($unionedType);
+        }
+
+        return new AttributeAwareUnionTypeNode($unionedArrayType);
+    }
 }