diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java
index 5470af626d0..d209caad2e3 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CppRestSdkClientCodegen.java
@@ -208,7 +208,7 @@ public class CppRestSdkClientCodegen extends AbstractCppCodegen {
         if (importMapping.containsKey(name)) {
             return importMapping.get(name);
         } else {
-            return "#include \"" + sanitizeName(name) + ".h\"";
+            return "#include \"" + toModelFilename(name) + ".h\"";
         }
     }
 
diff --git a/modules/openapi-generator/src/main/resources/cpp-rest-sdk-client/model-source.mustache b/modules/openapi-generator/src/main/resources/cpp-rest-sdk-client/model-source.mustache
index a27bf11168f..1805e44d58d 100644
--- a/modules/openapi-generator/src/main/resources/cpp-rest-sdk-client/model-source.mustache
+++ b/modules/openapi-generator/src/main/resources/cpp-rest-sdk-client/model-source.mustache
@@ -1,7 +1,7 @@
 {{>licenseInfo}}
 {{#models}}{{#model}}
 
-#include "{{classname}}.h"
+#include "{{classFilename}}.h"
 
 {{#modelNamespaceDeclarations}}
 namespace {{this}} {
diff --git a/samples/client/petstore/cpp-restsdk/.openapi-generator/VERSION b/samples/client/petstore/cpp-restsdk/.openapi-generator/VERSION
index 2c6109e5bb8..afa63656064 100644
--- a/samples/client/petstore/cpp-restsdk/.openapi-generator/VERSION
+++ b/samples/client/petstore/cpp-restsdk/.openapi-generator/VERSION
@@ -1 +1 @@
-3.3.4
\ No newline at end of file
+4.0.0-SNAPSHOT
\ No newline at end of file