diff --git a/src/Compiler/MapperFactory/DefaultMapperCompilerFactory.php b/src/Compiler/MapperFactory/DefaultMapperCompilerFactory.php
index 5452847..ecc3fd2 100644
--- a/src/Compiler/MapperFactory/DefaultMapperCompilerFactory.php
+++ b/src/Compiler/MapperFactory/DefaultMapperCompilerFactory.php
@@ -19,6 +19,7 @@
 use PHPStan\PhpDocParser\Ast\Type\IdentifierTypeNode;
 use PHPStan\PhpDocParser\Ast\Type\NullableTypeNode;
 use PHPStan\PhpDocParser\Ast\Type\TypeNode;
+use PHPStan\PhpDocParser\Ast\Type\UnionTypeNode;
 use PHPStan\PhpDocParser\Lexer\Lexer;
 use PHPStan\PhpDocParser\Parser\PhpDocParser;
 use PHPStan\PhpDocParser\Parser\TokenIterator;
@@ -57,6 +58,7 @@
 use function count;
 use function enum_exists;
 use function interface_exists;
+use function strcasecmp;
 use function strtolower;
 use function substr;
 
@@ -175,6 +177,23 @@ public function create(TypeNode $type, array $options = []): MapperCompiler
             return new MapArrayShape($items, $type->sealed);
         }
 
+        if ($type instanceof UnionTypeNode) {
+            $isNullable = false;
+            $subTypesWithoutNull = [];
+
+            foreach ($type->types as $subType) {
+                if ($subType instanceof IdentifierTypeNode && strcasecmp($subType->name, 'null') === 0) {
+                    $isNullable = true;
+                } else {
+                    $subTypesWithoutNull[] = $subType;
+                }
+            }
+
+            if ($isNullable && count($subTypesWithoutNull) === 1) {
+                return new MapNullable($this->createInner($subTypesWithoutNull[0], $options));
+            }
+        }
+
         throw CannotCreateMapperCompilerException::fromType($type);
     }
 
diff --git a/tests/Compiler/MapperFactory/DefaultMapperCompilerFactoryTest.php b/tests/Compiler/MapperFactory/DefaultMapperCompilerFactoryTest.php
index 0042215..8a0a34d 100644
--- a/tests/Compiler/MapperFactory/DefaultMapperCompilerFactoryTest.php
+++ b/tests/Compiler/MapperFactory/DefaultMapperCompilerFactoryTest.php
@@ -174,6 +174,18 @@ public static function provideCreateOkData(): iterable
             new MapString(),
         ];
 
+        yield '?int' => [
+            '?int',
+            [],
+            new MapNullable(new MapInt()),
+        ];
+
+        yield 'int|null' => [
+            'int|null',
+            [],
+            new MapNullable(new MapInt()),
+        ];
+
         yield 'int[]' => [
             'int[]',
             [],