diff --git a/src/Resources/Zone.php b/src/Resources/Zone.php
index 2540c81..c3248f0 100644
--- a/src/Resources/Zone.php
+++ b/src/Resources/Zone.php
@@ -353,7 +353,7 @@ public function setNsec3param(?string $nsec3param): self
     {
         // If set to null, return,
         if (is_null($nsec3param)) {
-            $this->nsec3param = null;
+            $this->nsec3param = "";
 
             return $this;
         }
diff --git a/tests/Resources/ZoneTest.php b/tests/Resources/ZoneTest.php
index 8bdafff..79c0cfc 100644
--- a/tests/Resources/ZoneTest.php
+++ b/tests/Resources/ZoneTest.php
@@ -116,7 +116,7 @@ public function testSetEmptyNsec3param(): void
     {
         $zone = new Zone();
         $zone->setNsec3param(null);
-        $this->assertNull($zone->getNsec3param());
+        $this->assertEmpty($zone->getNsec3param());
     }
 
     public function testSetNsec3paramInvalidAlgorithm(): void
diff --git a/tests/ZoneTest.php b/tests/ZoneTest.php
index 1956791..a3b5522 100644
--- a/tests/ZoneTest.php
+++ b/tests/ZoneTest.php
@@ -271,7 +271,7 @@ public function testSetEmptyNsec3param(): void
         $connector = Mockery::mock(Connector::class);
         $connector->shouldReceive('put')->withArgs(['zones/test.nl.', Mockery::on(function ($transformer) {
             $transformed = $transformer->transform();
-            $this->assertNull($transformed->nsec3param);
+            $this->assertEmpty($transformed->nsec3param);
 
             return true;
         })])->once()->andReturn([]);