diff --git a/ZertoApiWrapper/Public/Get-ZADatastore.ps1 b/ZertoApiWrapper/Public/Get-ZADatastore.ps1
index 8f12ddb..60bdc9e 100644
--- a/ZertoApiWrapper/Public/Get-ZADatastore.ps1
+++ b/ZertoApiWrapper/Public/Get-ZADatastore.ps1
@@ -29,6 +29,7 @@ function Get-ZADatastore {
             ParameterSetName = "datastore",
             Mandatory = $true
         )]
+        [ValidateNotNullOrEmpty()]
         [string]$datastoreIdentifier
 
     )
diff --git a/ZertoApiWrapper/Public/Get-ZAVolume.ps1 b/ZertoApiWrapper/Public/Get-ZAVolume.ps1
index 554f2ad..662448e 100644
--- a/ZertoApiWrapper/Public/Get-ZAVolume.ps1
+++ b/ZertoApiWrapper/Public/Get-ZAVolume.ps1
@@ -33,6 +33,7 @@ function Get-ZAVolume {
             Mandatory,
             ParameterSetName = "VpgIdentifier"
         )]
+        [ValidateNotNullOrEmpty()]
         [string]$vpgIdentifier
 
     )