diff --git a/modules/openapi-generator/src/main/resources/powershell/model_simple.mustache b/modules/openapi-generator/src/main/resources/powershell/model_simple.mustache
index 6929c038a11..6e7eadef78d 100644
--- a/modules/openapi-generator/src/main/resources/powershell/model_simple.mustache
+++ b/modules/openapi-generator/src/main/resources/powershell/model_simple.mustache
@@ -130,6 +130,14 @@ function ConvertFrom-{{{apiNamePrefix}}}JsonTo{{{classname}}} {
 
         $JsonParameters = ConvertFrom-Json -InputObject $Json
 
+        # check if Json contains properties not defined in {{{apiNamePrefix}}}{{{classname}}}
+        $AllProperties = ({{#allVars}}"{{{baseName}}}"{{^-last}}, {{/-last}}{{/allVars}})
+        foreach ($name in $JsonParameters.PsObject.Properties.Name) {
+            if (!($AllProperties.Contains($name))) {
+                throw "Error! JSON key '$name' not found in the properties: $($AllProperties)"
+            }
+        }
+
         {{#requiredVars}}
         {{#-first}}
         If ([string]::IsNullOrEmpty($Json) -or $Json -eq "{}") { # empty json
diff --git a/samples/client/petstore/powershell/.openapi-generator/FILES b/samples/client/petstore/powershell/.openapi-generator/FILES
new file mode 100644
index 00000000000..4708e0914a5
--- /dev/null
+++ b/samples/client/petstore/powershell/.openapi-generator/FILES
@@ -0,0 +1,33 @@
+Build.ps1
+README.md
+appveyor.yml
+docs/ApiResponse.md
+docs/Category.md
+docs/InlineObject.md
+docs/InlineObject1.md
+docs/Order.md
+docs/PSPetApi.md
+docs/PSStoreApi.md
+docs/PSUserApi.md
+docs/Pet.md
+docs/Tag.md
+docs/User.md
+src/PSPetstore/Api/PSPetApi.ps1
+src/PSPetstore/Api/PSStoreApi.ps1
+src/PSPetstore/Api/PSUserApi.ps1
+src/PSPetstore/Client/PSConfiguration.ps1
+src/PSPetstore/Model/ApiResponse.ps1
+src/PSPetstore/Model/Category.ps1
+src/PSPetstore/Model/InlineObject.ps1
+src/PSPetstore/Model/InlineObject1.ps1
+src/PSPetstore/Model/Order.ps1
+src/PSPetstore/Model/Pet.ps1
+src/PSPetstore/Model/Tag.ps1
+src/PSPetstore/Model/User.ps1
+src/PSPetstore/PSPetstore.psm1
+src/PSPetstore/Private/Get-CommonParameters.ps1
+src/PSPetstore/Private/Out-DebugParameter.ps1
+src/PSPetstore/Private/PSApiClient.ps1
+src/PSPetstore/Private/PSHttpSignatureAuth.ps1
+src/PSPetstore/Private/PSRSAEncryptionProvider.cs
+src/PSPetstore/en-US/about_PSPetstore.help.txt
diff --git a/samples/client/petstore/powershell/src/PSPetstore/Model/ApiResponse.ps1 b/samples/client/petstore/powershell/src/PSPetstore/Model/ApiResponse.ps1
index 098775df7ee..1cc58e9d5dc 100644
--- a/samples/client/petstore/powershell/src/PSPetstore/Model/ApiResponse.ps1
+++ b/samples/client/petstore/powershell/src/PSPetstore/Model/ApiResponse.ps1
@@ -85,6 +85,14 @@ function ConvertFrom-PSJsonToApiResponse {
 
         $JsonParameters = ConvertFrom-Json -InputObject $Json
 
+        # check if Json contains properties not defined in PSApiResponse
+        $AllProperties = ("code", "type", "message")
+        foreach ($name in $JsonParameters.PsObject.Properties.Name) {
+            if (!($AllProperties.Contains($name))) {
+                throw "Error! JSON key '$name' not found in the properties: $($AllProperties)"
+            }
+        }
+
         if (!([bool]($JsonParameters.PSobject.Properties.name -match "code"))) { #optional property not found
             $Code = $null
         } else {
diff --git a/samples/client/petstore/powershell/src/PSPetstore/Model/Category.ps1 b/samples/client/petstore/powershell/src/PSPetstore/Model/Category.ps1
index cb85b6c2e73..5d5e93da8e5 100644
--- a/samples/client/petstore/powershell/src/PSPetstore/Model/Category.ps1
+++ b/samples/client/petstore/powershell/src/PSPetstore/Model/Category.ps1
@@ -79,6 +79,14 @@ function ConvertFrom-PSJsonToCategory {
 
         $JsonParameters = ConvertFrom-Json -InputObject $Json
 
+        # check if Json contains properties not defined in PSCategory
+        $AllProperties = ("id", "name")
+        foreach ($name in $JsonParameters.PsObject.Properties.Name) {
+            if (!($AllProperties.Contains($name))) {
+                throw "Error! JSON key '$name' not found in the properties: $($AllProperties)"
+            }
+        }
+
         if (!([bool]($JsonParameters.PSobject.Properties.name -match "id"))) { #optional property not found
             $Id = $null
         } else {
diff --git a/samples/client/petstore/powershell/src/PSPetstore/Model/InlineObject.ps1 b/samples/client/petstore/powershell/src/PSPetstore/Model/InlineObject.ps1
index 97ca828980d..fbfde854a24 100644
--- a/samples/client/petstore/powershell/src/PSPetstore/Model/InlineObject.ps1
+++ b/samples/client/petstore/powershell/src/PSPetstore/Model/InlineObject.ps1
@@ -78,6 +78,14 @@ function ConvertFrom-PSJsonToInlineObject {
 
         $JsonParameters = ConvertFrom-Json -InputObject $Json
 
+        # check if Json contains properties not defined in PSInlineObject
+        $AllProperties = ("name", "status")
+        foreach ($name in $JsonParameters.PsObject.Properties.Name) {
+            if (!($AllProperties.Contains($name))) {
+                throw "Error! JSON key '$name' not found in the properties: $($AllProperties)"
+            }
+        }
+
         if (!([bool]($JsonParameters.PSobject.Properties.name -match "name"))) { #optional property not found
             $Name = $null
         } else {
diff --git a/samples/client/petstore/powershell/src/PSPetstore/Model/InlineObject1.ps1 b/samples/client/petstore/powershell/src/PSPetstore/Model/InlineObject1.ps1
index 98d26313ae5..cfd49e06365 100644
--- a/samples/client/petstore/powershell/src/PSPetstore/Model/InlineObject1.ps1
+++ b/samples/client/petstore/powershell/src/PSPetstore/Model/InlineObject1.ps1
@@ -78,6 +78,14 @@ function ConvertFrom-PSJsonToInlineObject1 {
 
         $JsonParameters = ConvertFrom-Json -InputObject $Json
 
+        # check if Json contains properties not defined in PSInlineObject1
+        $AllProperties = ("additionalMetadata", "file")
+        foreach ($name in $JsonParameters.PsObject.Properties.Name) {
+            if (!($AllProperties.Contains($name))) {
+                throw "Error! JSON key '$name' not found in the properties: $($AllProperties)"
+            }
+        }
+
         if (!([bool]($JsonParameters.PSobject.Properties.name -match "additionalMetadata"))) { #optional property not found
             $AdditionalMetadata = $null
         } else {
diff --git a/samples/client/petstore/powershell/src/PSPetstore/Model/Order.ps1 b/samples/client/petstore/powershell/src/PSPetstore/Model/Order.ps1
index 29f88643cea..d74819356ad 100644
--- a/samples/client/petstore/powershell/src/PSPetstore/Model/Order.ps1
+++ b/samples/client/petstore/powershell/src/PSPetstore/Model/Order.ps1
@@ -107,6 +107,14 @@ function ConvertFrom-PSJsonToOrder {
 
         $JsonParameters = ConvertFrom-Json -InputObject $Json
 
+        # check if Json contains properties not defined in PSOrder
+        $AllProperties = ("id", "petId", "quantity", "shipDate", "status", "complete")
+        foreach ($name in $JsonParameters.PsObject.Properties.Name) {
+            if (!($AllProperties.Contains($name))) {
+                throw "Error! JSON key '$name' not found in the properties: $($AllProperties)"
+            }
+        }
+
         if (!([bool]($JsonParameters.PSobject.Properties.name -match "id"))) { #optional property not found
             $Id = $null
         } else {
diff --git a/samples/client/petstore/powershell/src/PSPetstore/Model/Pet.ps1 b/samples/client/petstore/powershell/src/PSPetstore/Model/Pet.ps1
index df59392c973..d9c53786d54 100644
--- a/samples/client/petstore/powershell/src/PSPetstore/Model/Pet.ps1
+++ b/samples/client/petstore/powershell/src/PSPetstore/Model/Pet.ps1
@@ -115,6 +115,14 @@ function ConvertFrom-PSJsonToPet {
 
         $JsonParameters = ConvertFrom-Json -InputObject $Json
 
+        # check if Json contains properties not defined in PSPet
+        $AllProperties = ("id", "category", "name", "photoUrls", "tags", "status")
+        foreach ($name in $JsonParameters.PsObject.Properties.Name) {
+            if (!($AllProperties.Contains($name))) {
+                throw "Error! JSON key '$name' not found in the properties: $($AllProperties)"
+            }
+        }
+
         If ([string]::IsNullOrEmpty($Json) -or $Json -eq "{}") { # empty json
             throw "Error! Empty JSON cannot be serialized due to the required property `name` missing."
         }
diff --git a/samples/client/petstore/powershell/src/PSPetstore/Model/Tag.ps1 b/samples/client/petstore/powershell/src/PSPetstore/Model/Tag.ps1
index 30ec0ab8045..0f0044ef35c 100644
--- a/samples/client/petstore/powershell/src/PSPetstore/Model/Tag.ps1
+++ b/samples/client/petstore/powershell/src/PSPetstore/Model/Tag.ps1
@@ -78,6 +78,14 @@ function ConvertFrom-PSJsonToTag {
 
         $JsonParameters = ConvertFrom-Json -InputObject $Json
 
+        # check if Json contains properties not defined in PSTag
+        $AllProperties = ("id", "name")
+        foreach ($name in $JsonParameters.PsObject.Properties.Name) {
+            if (!($AllProperties.Contains($name))) {
+                throw "Error! JSON key '$name' not found in the properties: $($AllProperties)"
+            }
+        }
+
         if (!([bool]($JsonParameters.PSobject.Properties.name -match "id"))) { #optional property not found
             $Id = $null
         } else {
diff --git a/samples/client/petstore/powershell/src/PSPetstore/Model/User.ps1 b/samples/client/petstore/powershell/src/PSPetstore/Model/User.ps1
index c3a6568d3d8..493322216a2 100644
--- a/samples/client/petstore/powershell/src/PSPetstore/Model/User.ps1
+++ b/samples/client/petstore/powershell/src/PSPetstore/Model/User.ps1
@@ -121,6 +121,14 @@ function ConvertFrom-PSJsonToUser {
 
         $JsonParameters = ConvertFrom-Json -InputObject $Json
 
+        # check if Json contains properties not defined in PSUser
+        $AllProperties = ("id", "username", "firstName", "lastName", "email", "password", "phone", "userStatus")
+        foreach ($name in $JsonParameters.PsObject.Properties.Name) {
+            if (!($AllProperties.Contains($name))) {
+                throw "Error! JSON key '$name' not found in the properties: $($AllProperties)"
+            }
+        }
+
         if (!([bool]($JsonParameters.PSobject.Properties.name -match "id"))) { #optional property not found
             $Id = $null
         } else {