diff --git a/samples/client/petstore/c/api/PetAPI.h b/samples/client/petstore/c/api/PetAPI.h
index f223b60a0b8d..c24b44305cf5 100644
--- a/samples/client/petstore/c/api/PetAPI.h
+++ b/samples/client/petstore/c/api/PetAPI.h
@@ -8,6 +8,10 @@
 #include "../model/api_response.h"
 #include "../model/pet.h"
 
+#undef stdin
+#undef stderr
+#undef stdout
+
 // Enum STATUS for PetAPI_findPetsByStatus
 typedef enum  { openapi_petstore_findPetsByStatus_STATUS_NULL = 0, openapi_petstore_findPetsByStatus_STATUS_available, openapi_petstore_findPetsByStatus_STATUS_pending, openapi_petstore_findPetsByStatus_STATUS_sold } openapi_petstore_findPetsByStatus_status_e;
 
diff --git a/samples/client/petstore/c/api/StoreAPI.h b/samples/client/petstore/c/api/StoreAPI.h
index 43bdf7583767..21985044c200 100644
--- a/samples/client/petstore/c/api/StoreAPI.h
+++ b/samples/client/petstore/c/api/StoreAPI.h
@@ -7,6 +7,10 @@
 #include "../include/binary.h"
 #include "../model/order.h"
 
+#undef stdin
+#undef stderr
+#undef stdout
+
 
 // Delete purchase order by ID
 //
diff --git a/samples/client/petstore/c/api/UserAPI.h b/samples/client/petstore/c/api/UserAPI.h
index b0a60accdab9..d6e43056f13b 100644
--- a/samples/client/petstore/c/api/UserAPI.h
+++ b/samples/client/petstore/c/api/UserAPI.h
@@ -7,6 +7,10 @@
 #include "../include/binary.h"
 #include "../model/user.h"
 
+#undef stdin
+#undef stderr
+#undef stdout
+
 
 // Create user
 //
diff --git a/samples/client/petstore/c/model/api_response.h b/samples/client/petstore/c/model/api_response.h
index d64dcbacedd9..fe0c87f9a5f9 100644
--- a/samples/client/petstore/c/model/api_response.h
+++ b/samples/client/petstore/c/model/api_response.h
@@ -16,6 +16,10 @@
 typedef struct api_response_t api_response_t;
 
 
+#undef stdin
+#undef stderr
+#undef stdout
+
 
 
 typedef struct api_response_t {
diff --git a/samples/client/petstore/c/model/category.h b/samples/client/petstore/c/model/category.h
index ec9efd6ccf60..9ef031f5c692 100644
--- a/samples/client/petstore/c/model/category.h
+++ b/samples/client/petstore/c/model/category.h
@@ -16,6 +16,10 @@
 typedef struct category_t category_t;
 
 
+#undef stdin
+#undef stderr
+#undef stdout
+
 
 
 typedef struct category_t {
diff --git a/samples/client/petstore/c/model/order.h b/samples/client/petstore/c/model/order.h
index 32914a227499..099ce89d8b8a 100644
--- a/samples/client/petstore/c/model/order.h
+++ b/samples/client/petstore/c/model/order.h
@@ -16,6 +16,10 @@
 typedef struct order_t order_t;
 
 
+#undef stdin
+#undef stderr
+#undef stdout
+
 // Enum STATUS for order
 
 typedef enum  { openapi_petstore_order_STATUS_NULL = 0, openapi_petstore_order_STATUS_placed, openapi_petstore_order_STATUS_approved, openapi_petstore_order_STATUS_delivered } openapi_petstore_order_STATUS_e;
diff --git a/samples/client/petstore/c/model/pet.h b/samples/client/petstore/c/model/pet.h
index d74025510143..561d1ac508b2 100644
--- a/samples/client/petstore/c/model/pet.h
+++ b/samples/client/petstore/c/model/pet.h
@@ -18,6 +18,10 @@ typedef struct pet_t pet_t;
 #include "category.h"
 #include "tag.h"
 
+#undef stdin
+#undef stderr
+#undef stdout
+
 // Enum STATUS for pet
 
 typedef enum  { openapi_petstore_pet_STATUS_NULL = 0, openapi_petstore_pet_STATUS_available, openapi_petstore_pet_STATUS_pending, openapi_petstore_pet_STATUS_sold } openapi_petstore_pet_STATUS_e;
diff --git a/samples/client/petstore/c/model/tag.h b/samples/client/petstore/c/model/tag.h
index 9e7b5d053a9d..0917db85e5c2 100644
--- a/samples/client/petstore/c/model/tag.h
+++ b/samples/client/petstore/c/model/tag.h
@@ -16,6 +16,10 @@
 typedef struct tag_t tag_t;
 
 
+#undef stdin
+#undef stderr
+#undef stdout
+
 
 
 typedef struct tag_t {
diff --git a/samples/client/petstore/c/model/user.h b/samples/client/petstore/c/model/user.h
index 45fa42c3f91c..15f25b12c620 100644
--- a/samples/client/petstore/c/model/user.h
+++ b/samples/client/petstore/c/model/user.h
@@ -16,6 +16,10 @@
 typedef struct user_t user_t;
 
 
+#undef stdin
+#undef stderr
+#undef stdout
+
 
 
 typedef struct user_t {
diff --git a/samples/client/petstore/c/src/apiClient.c b/samples/client/petstore/c/src/apiClient.c
index 2ab296b2e637..ce2f522cda28 100644
--- a/samples/client/petstore/c/src/apiClient.c
+++ b/samples/client/petstore/c/src/apiClient.c
@@ -476,7 +476,7 @@ size_t writeDataCallback(void *buffer, size_t size, size_t nmemb, void *userp) {
     size_t size_this_time = nmemb * size;
     apiClient_t *apiClient = (apiClient_t *)userp;
     apiClient->dataReceived = (char *)realloc( apiClient->dataReceived, apiClient->dataReceivedLen + size_this_time + 1);
-    memcpy(apiClient->dataReceived + apiClient->dataReceivedLen, buffer, size_this_time);
+    memcpy((char *)apiClient->dataReceived + apiClient->dataReceivedLen, buffer, size_this_time);
     apiClient->dataReceivedLen += size_this_time;
     ((char*)apiClient->dataReceived)[apiClient->dataReceivedLen] = '\0'; // the space size of (apiClient->dataReceived) = dataReceivedLen + 1
     if (apiClient->data_callback_func) {