diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java
index c288575f695..4bef1d6fc66 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppPistacheServerCodegen.java
@@ -246,6 +246,12 @@ public class CppPistacheServerCodegen extends AbstractCppCodegen {
             }
             op.vendorExtensions.put("x-codegen-pistache-consumesJson", consumeJson);
             op.vendorExtensions.put("x-codegen-pistache-isParsingSupported", isParsingSupported);
+            for(String hdr : op.imports) {
+                if(importMapping.containsKey(hdr)) {
+                    continue;
+                }
+                additionalProperties.put("hasModelImport", true);
+            }
         }
 
         return objs;
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-header.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-header.mustache
index 1ede8d1a982..9db55ca4bac 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-header.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-header.mustache
@@ -23,7 +23,8 @@
 namespace {{this}} {
 {{/apiNamespaceDeclarations}}
 
-using namespace {{modelNamespace}};
+{{#hasModelImport}}
+using namespace {{modelNamespace}};{{/hasModelImport}}
 
 class {{declspec}} {{classname}} {
 public:
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-header.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-header.mustache
index 3aa6d5bc421..49c274d8fd7 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-header.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-header.mustache
@@ -26,7 +26,8 @@
 namespace {{this}} {
 {{/apiNamespaceDeclarations}}
 
-using namespace {{modelNamespace}};
+{{#hasModelImport}}
+using namespace {{modelNamespace}};{{/hasModelImport}}
 
 class {{classname}}Impl : public {{apiNamespace}}::{{classname}} {
 public:
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-source.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-source.mustache
index a3babcd5cad..d6ba91e15af 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-source.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-impl-source.mustache
@@ -7,7 +7,8 @@
 namespace {{this}} {
 {{/apiNamespaceDeclarations}}
 
-using namespace {{modelNamespace}};
+{{#hasModelImport}}
+using namespace {{modelNamespace}};{{/hasModelImport}}
 
 {{classname}}Impl::{{classname}}Impl(Pistache::Address addr)
     : {{classname}}(addr)
diff --git a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-source.mustache b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-source.mustache
index d6aa9becb04..c40c67eaa74 100644
--- a/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-source.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-pistache-server/api-source.mustache
@@ -7,7 +7,8 @@
 namespace {{this}} {
 {{/apiNamespaceDeclarations}}
 
-using namespace {{modelNamespace}};
+{{#hasModelImport}}
+using namespace {{modelNamespace}};{{/hasModelImport}}
 
 {{classname}}::{{classname}}(Pistache::Address addr)
     : httpEndpoint(addr)