diff --git a/modules/order/tests/src/Kernel/AdjustmentTest.php b/modules/order/tests/src/Kernel/AdjustmentTest.php
index 3e76337b..2d3d91b0 100644
--- a/modules/order/tests/src/Kernel/AdjustmentTest.php
+++ b/modules/order/tests/src/Kernel/AdjustmentTest.php
@@ -139,6 +139,11 @@ class AdjustmentTest extends OrderKernelTestBase {
     $this->assertTrue($adjustment->isIncluded());
     $this->assertTrue($adjustment->isLocked());
     $this->assertEquals($definition, $adjustment->toArray());
+
+    // Test adjustment with percentage equals zero.
+    $definition['percentage'] = '0';
+    $adjustment = new Adjustment($definition);
+    $this->assertEquals('0', $adjustment->getPercentage());
   }
 
   /**