diff --git a/modules/openapi-generator/src/main/resources/powershell/Org.OpenAPITools.psm1.mustache b/modules/openapi-generator/src/main/resources/powershell/Org.OpenAPITools.psm1.mustache
index 7714f348b49..32795eca376 100644
--- a/modules/openapi-generator/src/main/resources/powershell/Org.OpenAPITools.psm1.mustache
+++ b/modules/openapi-generator/src/main/resources/powershell/Org.OpenAPITools.psm1.mustache
@@ -1,6 +1,14 @@
 {{>partial_header}}
 #region Import functions
 
+# define the following classes in PowerShell
+try {
+    Add-Type -AssemblyName System.Web -ErrorAction Ignore | Out-Null
+    Add-Type -AssemblyName System.Net -ErrorAction Ignore | Out-Null
+} catch {
+    Write-Verbose $_
+}
+
 # set $ErrorActionPreference to 'Stop' globally
 $ErrorActionPreference = 'Stop'
 
diff --git a/samples/client/petstore/powershell/src/PSPetstore/PSPetstore.psm1 b/samples/client/petstore/powershell/src/PSPetstore/PSPetstore.psm1
index 9153f06cd47..bc8d8503afe 100644
--- a/samples/client/petstore/powershell/src/PSPetstore/PSPetstore.psm1
+++ b/samples/client/petstore/powershell/src/PSPetstore/PSPetstore.psm1
@@ -7,6 +7,14 @@
 
 #region Import functions
 
+# define the following classes in PowerShell
+try {
+    Add-Type -AssemblyName System.Web -ErrorAction Ignore | Out-Null
+    Add-Type -AssemblyName System.Net -ErrorAction Ignore | Out-Null
+} catch {
+    Write-Verbose $_
+}
+
 # set $ErrorActionPreference to 'Stop' globally
 $ErrorActionPreference = 'Stop'