diff --git a/src/Keboola/CsvTable/Table.php b/src/Keboola/CsvTable/Table.php
index 78b7591..1c88baf 100755
--- a/src/Keboola/CsvTable/Table.php
+++ b/src/Keboola/CsvTable/Table.php
@@ -22,7 +22,7 @@ class Table extends CsvWriter {
 	/** @var string */
 	protected $name;
 
-	/** @var bool */
+	/** @var bool|null */
 	protected $incremental = null;
 
 	/** @var array */
@@ -75,11 +75,20 @@ public function getAttributes(): array
 
 	public function setIncremental(bool $incremental): void
 	{
-		$this->incremental = (bool) $incremental;
+		$this->incremental = $incremental;
 	}
 
+	public function isIncrementalSet(): bool
+    {
+        return $this->incremental !== null;
+    }
+
 	public function getIncremental(): bool
 	{
+	    if ($this->incremental === null) {
+	        throw new \UnexpectedValueException('Incremental is not set.');
+        }
+
 		return $this->incremental;
 	}
 
diff --git a/tests/Keboola/CsvTable/TableTest.php b/tests/Keboola/CsvTable/TableTest.php
index 8662e76..87f5876 100755
--- a/tests/Keboola/CsvTable/TableTest.php
+++ b/tests/Keboola/CsvTable/TableTest.php
@@ -4,7 +4,7 @@
 use Keboola\CsvTable\Table;
 use PHPUnit\Framework\TestCase;
 
-class TempTest extends TestCase
+class TableTest extends TestCase
 {
 	public function testCreate()
 	{
@@ -60,4 +60,27 @@ public function testPrimaryKeyEmpty()
         $table = new Table('pk', ['id', 'user', 'data']);
         $this->assertNull($table->getPrimaryKey());
     }
+
+    public function testIncrementalNoValue()
+    {
+        $table = new Table('pk', ['id', 'user', 'data']);
+        $this->assertFalse($table->isIncrementalSet());
+
+        $this->expectException(\UnexpectedValueException::class);
+        $this->expectExceptionMessage('Incremental is not set.');
+        $table->getIncremental();
+    }
+
+    public function testIncrementalSetValue()
+    {
+        $table = new Table('pk', ['id', 'user', 'data']);
+
+        $table->setIncremental(true);
+        $this->assertTrue($table->isIncrementalSet());
+        $this->assertTrue($table->getIncremental());
+
+        $table->setIncremental(false);
+        $this->assertTrue($table->isIncrementalSet());
+        $this->assertFalse($table->getIncremental());
+    }
 }