diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCppCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCppCodegen.java
index 8a2c3c5eb7af..c4dc7b5fd92d 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCppCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCppCodegen.java
@@ -194,6 +194,11 @@ public String toModelName(String type) {
         }
     }
 
+    @Override
+    public String toEnumValue(String value, String datatype) {
+        return escapeText(value);
+    }
+
     @Override
     public String toVarName(String name) {
         if (typeMapping.keySet().contains(name) || typeMapping.values().contains(name)
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-header.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-header.mustache
index b999e5997b4e..c16fdbb09467 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-header.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-header.mustache
@@ -25,7 +25,16 @@ class {{declspec}} {{classname}}
 public:
     {{classname}}();
     virtual ~{{classname}}();
-
+{{#isEnum}}{{#allowableValues}}
+    enum class e{{classname}} {
+    // To have a valid default value.
+    // Avoiding nameclashes with user defined
+    // enum values
+    INVALID_VALUE_OPENAPI_GENERATED = 0,
+    {{#enumVars}}
+    {{{name}}}{{^-last}}, {{/-last}}
+    {{/enumVars}}
+    };{{/allowableValues}}{{/isEnum}}
     void validate();
 
     /////////////////////////////////////////////
@@ -40,6 +49,10 @@ public:
     bool {{nameInCamelCase}}IsSet() const;
     void unset{{name}}();{{/required}}
     {{/vars}}
+    {{#isEnum}}
+    {{classname}}::e{{classname}} getValue() const;
+    void setValue({{classname}}::e{{classname}} value);
+    {{/isEnum}}
 
     friend void to_json(nlohmann::json& j, const {{classname}}& o);
     friend void from_json(const nlohmann::json& j, {{classname}}& o);
@@ -49,6 +62,9 @@ protected:
     {{^required}}
     bool m_{{name}}IsSet;{{/required}}
     {{/vars}}
+    {{#isEnum}}
+    {{classname}}::e{{classname}} m_value = {{classname}}::e{{classname}}::INVALID_VALUE_OPENAPI_GENERATED;
+    {{/isEnum}}
 };
 
 {{#modelNamespaceDeclarations}}
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-source.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-source.mustache
index 03b8d574df46..d603dc2186e0 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-source.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/model-source.mustache
@@ -2,6 +2,8 @@
 {{#models}}{{#model}}
 
 #include "{{classname}}.h"
+{{#isEnum}}#include <stdexcept>
+#include <sstream>{{/isEnum}}
 
 {{#modelNamespaceDeclarations}}
 namespace {{this}} {
@@ -32,6 +34,20 @@ void to_json(nlohmann::json& j, const {{classname}}& o)
     {{#required}}j["{{baseName}}"] = o.m_{{name}};{{/required}}{{^required}}if(o.{{nameInCamelCase}}IsSet(){{#isContainer}} || !o.m_{{name}}.empty(){{/isContainer}})
         j["{{baseName}}"] = o.m_{{name}};{{/required}}
     {{/vars}}
+    {{#isEnum}}{{#allowableValues}}
+    switch (o.getValue())
+    {
+        {{#enumVars}}
+        {{#-first}}
+        case {{classname}}::e{{classname}}::INVALID_VALUE_OPENAPI_GENERATED:
+            j = "INVALID_VALUE_OPENAPI_GENERATED";
+            break;
+        {{/-first}}
+        case {{classname}}::e{{classname}}::{{name}}:
+            j = "{{value}}";
+            break;
+        {{/enumVars}}
+    }{{/allowableValues}}{{/isEnum}}
 }
 
 void from_json(const nlohmann::json& j, {{classname}}& o)
@@ -43,6 +59,19 @@ void from_json(const nlohmann::json& j, {{classname}}& o)
         o.m_{{name}}IsSet = true;
     } {{/required}}
     {{/vars}}
+    {{#isEnum}}{{#allowableValues}}
+    auto s = j.get<std::string>();
+    {{#enumVars}}
+    {{#-first}}if{{/-first}}{{^-first}}else if{{/-first}} (s == "{{value}}") {
+     o.setValue({{classname}}::e{{classname}}::{{name}});
+    } {{#-last}} else {
+     std::stringstream ss;
+     ss << "Unexpected value " << s << " in json"
+        << " cannot be converted to enum of type"
+        << " {{classname}}::e{{classname}}";
+     throw std::invalid_argument(ss.str());
+    } {{/-last}}
+{{/enumVars}}{{/allowableValues}}{{/isEnum}}
 }
 
 {{#vars}}{{{dataType}}}{{#isContainer}}&{{/isContainer}} {{classname}}::{{getter}}(){{^isContainer}} const{{/isContainer}}
@@ -64,6 +93,14 @@ void {{classname}}::unset{{name}}()
 }
 {{/required}}
 {{/vars}}
+{{#isEnum}}{{classname}}::e{{classname}} {{classname}}::getValue() const
+{
+    return m_value;
+}
+void {{classname}}::setValue({{classname}}::e{{classname}} value)
+{
+    m_value = value;
+}{{/isEnum}}
 
 {{#modelNamespaceDeclarations}}
 }
diff --git a/samples/server/petstore/cpp-pistache/.openapi-generator/VERSION b/samples/server/petstore/cpp-pistache/.openapi-generator/VERSION
index d99e7162d01f..c30f0ec2be7f 100644
--- a/samples/server/petstore/cpp-pistache/.openapi-generator/VERSION
+++ b/samples/server/petstore/cpp-pistache/.openapi-generator/VERSION
@@ -1 +1 @@
-5.0.0-SNAPSHOT
\ No newline at end of file
+5.1.0-SNAPSHOT
\ No newline at end of file
diff --git a/samples/server/petstore/cpp-pistache/model/ApiResponse.cpp b/samples/server/petstore/cpp-pistache/model/ApiResponse.cpp
index 77cd466e145f..4b9ca7419208 100644
--- a/samples/server/petstore/cpp-pistache/model/ApiResponse.cpp
+++ b/samples/server/petstore/cpp-pistache/model/ApiResponse.cpp
@@ -47,6 +47,7 @@ void to_json(nlohmann::json& j, const ApiResponse& o)
         j["type"] = o.m_Type;
     if(o.messageIsSet())
         j["message"] = o.m_Message;
+    
 }
 
 void from_json(const nlohmann::json& j, ApiResponse& o)
@@ -66,6 +67,7 @@ void from_json(const nlohmann::json& j, ApiResponse& o)
         j.at("message").get_to(o.m_Message);
         o.m_MessageIsSet = true;
     } 
+    
 }
 
 int32_t ApiResponse::getCode() const
@@ -120,6 +122,7 @@ void ApiResponse::unsetMessage()
     m_MessageIsSet = false;
 }
 
+
 }
 }
 }
diff --git a/samples/server/petstore/cpp-pistache/model/Category.cpp b/samples/server/petstore/cpp-pistache/model/Category.cpp
index 43ff1d490004..3b08114f61de 100644
--- a/samples/server/petstore/cpp-pistache/model/Category.cpp
+++ b/samples/server/petstore/cpp-pistache/model/Category.cpp
@@ -43,6 +43,7 @@ void to_json(nlohmann::json& j, const Category& o)
         j["id"] = o.m_Id;
     if(o.nameIsSet())
         j["name"] = o.m_Name;
+    
 }
 
 void from_json(const nlohmann::json& j, Category& o)
@@ -57,6 +58,7 @@ void from_json(const nlohmann::json& j, Category& o)
         j.at("name").get_to(o.m_Name);
         o.m_NameIsSet = true;
     } 
+    
 }
 
 int64_t Category::getId() const
@@ -94,6 +96,7 @@ void Category::unsetName()
     m_NameIsSet = false;
 }
 
+
 }
 }
 }
diff --git a/samples/server/petstore/cpp-pistache/model/Order.cpp b/samples/server/petstore/cpp-pistache/model/Order.cpp
index 82efbce6cb22..986cf6b24fa9 100644
--- a/samples/server/petstore/cpp-pistache/model/Order.cpp
+++ b/samples/server/petstore/cpp-pistache/model/Order.cpp
@@ -59,6 +59,7 @@ void to_json(nlohmann::json& j, const Order& o)
         j["status"] = o.m_Status;
     if(o.completeIsSet())
         j["complete"] = o.m_Complete;
+    
 }
 
 void from_json(const nlohmann::json& j, Order& o)
@@ -93,6 +94,7 @@ void from_json(const nlohmann::json& j, Order& o)
         j.at("complete").get_to(o.m_Complete);
         o.m_CompleteIsSet = true;
     } 
+    
 }
 
 int64_t Order::getId() const
@@ -198,6 +200,7 @@ void Order::unsetComplete()
     m_CompleteIsSet = false;
 }
 
+
 }
 }
 }
diff --git a/samples/server/petstore/cpp-pistache/model/Pet.cpp b/samples/server/petstore/cpp-pistache/model/Pet.cpp
index 0ff016b545f0..434b1339cd06 100644
--- a/samples/server/petstore/cpp-pistache/model/Pet.cpp
+++ b/samples/server/petstore/cpp-pistache/model/Pet.cpp
@@ -52,6 +52,7 @@ void to_json(nlohmann::json& j, const Pet& o)
         j["tags"] = o.m_Tags;
     if(o.statusIsSet())
         j["status"] = o.m_Status;
+    
 }
 
 void from_json(const nlohmann::json& j, Pet& o)
@@ -78,6 +79,7 @@ void from_json(const nlohmann::json& j, Pet& o)
         j.at("status").get_to(o.m_Status);
         o.m_StatusIsSet = true;
     } 
+    
 }
 
 int64_t Pet::getId() const
@@ -165,6 +167,7 @@ void Pet::unsetStatus()
     m_StatusIsSet = false;
 }
 
+
 }
 }
 }
diff --git a/samples/server/petstore/cpp-pistache/model/Tag.cpp b/samples/server/petstore/cpp-pistache/model/Tag.cpp
index 7f56fb2bcca9..cba759bad1d0 100644
--- a/samples/server/petstore/cpp-pistache/model/Tag.cpp
+++ b/samples/server/petstore/cpp-pistache/model/Tag.cpp
@@ -43,6 +43,7 @@ void to_json(nlohmann::json& j, const Tag& o)
         j["id"] = o.m_Id;
     if(o.nameIsSet())
         j["name"] = o.m_Name;
+    
 }
 
 void from_json(const nlohmann::json& j, Tag& o)
@@ -57,6 +58,7 @@ void from_json(const nlohmann::json& j, Tag& o)
         j.at("name").get_to(o.m_Name);
         o.m_NameIsSet = true;
     } 
+    
 }
 
 int64_t Tag::getId() const
@@ -94,6 +96,7 @@ void Tag::unsetName()
     m_NameIsSet = false;
 }
 
+
 }
 }
 }
diff --git a/samples/server/petstore/cpp-pistache/model/User.cpp b/samples/server/petstore/cpp-pistache/model/User.cpp
index 20ae06352f25..2db9316b75d9 100644
--- a/samples/server/petstore/cpp-pistache/model/User.cpp
+++ b/samples/server/petstore/cpp-pistache/model/User.cpp
@@ -67,6 +67,7 @@ void to_json(nlohmann::json& j, const User& o)
         j["phone"] = o.m_Phone;
     if(o.userStatusIsSet())
         j["userStatus"] = o.m_UserStatus;
+    
 }
 
 void from_json(const nlohmann::json& j, User& o)
@@ -111,6 +112,7 @@ void from_json(const nlohmann::json& j, User& o)
         j.at("userStatus").get_to(o.m_UserStatus);
         o.m_UserStatusIsSet = true;
     } 
+    
 }
 
 int64_t User::getId() const
@@ -250,6 +252,7 @@ void User::unsetUserStatus()
     m_UserStatusIsSet = false;
 }
 
+
 }
 }
 }