diff --git a/wmi2dokuwiki.ps1 b/wmi2dokuwiki.ps1
index 4016903..c15a78e 100644
--- a/wmi2dokuwiki.ps1
+++ b/wmi2dokuwiki.ps1
@@ -49,7 +49,9 @@ Write-Output ""
 Write-Output "^ Eigenschap        ^ Waarde ^"
 Write-Output "| Fabrikant         | $manufacturer |"
 Write-Output "| Productnaam       | $productName |"
-Write-Output "| Serienummer       | $serialNumber |"
+if ($null -ne $serialNumber) {
+    Write-Output "| Serienummer       | $serialNumber |"
+}
 Write-Output "| BIOS-versie       | $biosVersion |"
 Write-Output "| BIOS-datum        | $biosDate |"
 Write-Output "| CPU-model         | $cpuModel |"