diff --git a/reactos/dll/win32/wininet/inet_ntop.c b/reactos/dll/win32/wininet/inet_ntop.c
index f29d46d1625..1c5fe35dcb1 100644
--- a/reactos/dll/win32/wininet/inet_ntop.c
+++ b/reactos/dll/win32/wininet/inet_ntop.c
@@ -16,9 +16,6 @@
  * SOFTWARE.
  */
 
-#define ENOSPC 28
-#define EAFNOSUPPORT 52
-
 #ifndef IN6ADDRSZ
 #define	IN6ADDRSZ	16
 #endif
@@ -64,7 +61,7 @@ inet_ntop(int af, const void *src, char *dst, size_t size)
 		return (inet_ntop6(src, dst, size));
 #endif
 	default:
-		errno = EAFNOSUPPORT;
+		WSASetLastError(WSAEAFNOSUPPORT);
 		return (NULL);
 	}
 	/* NOTREACHED */
@@ -88,7 +85,7 @@ inet_ntop4(const u_char *src, char *dst, size_t size)
 	char tmp[sizeof "255.255.255.255"];
 
 	if (SPRINTF((tmp, fmt, src[0], src[1], src[2], src[3])) > size) {
-		errno = ENOSPC;
+		WSASetLastError(WSAEINVAL);
 		return (NULL);
 	}
 	strcpy(dst, tmp);
@@ -182,7 +179,7 @@ inet_ntop6(const u_char *src, char *dst, size_t size)
 	 * Check for overflow, copy, and we're done.
 	 */
 	if ((size_t)(tp - tmp) > size) {
-		errno = ENOSPC;
+		WSASetLastError(WSAEINVAL);
 		return (NULL);
 	}
 	strcpy(dst, tmp);
diff --git a/reactos/dll/win32/wininet/internet.h b/reactos/dll/win32/wininet/internet.h
index a531ccd752f..d675f0fd3ba 100644
--- a/reactos/dll/win32/wininet/internet.h
+++ b/reactos/dll/win32/wininet/internet.h
@@ -47,10 +47,6 @@
 #define ioctlsocket ioctl
 #endif /* __MINGW32__ */
 
-/* ReactOS-specific definitions */
-#undef CP_UNIXCP
-#define CP_UNIXCP   CP_THREAD_ACP
-
 /* used for netconnection.c stuff */
 typedef struct
 {
@@ -441,7 +437,7 @@ DWORD NETCON_recv(WININET_NETCONNECTION *connection, void *buf, size_t len, int
 BOOL NETCON_query_data_available(WININET_NETCONNECTION *connection, DWORD *available);
 LPCVOID NETCON_GetCert(WININET_NETCONNECTION *connection);
 DWORD NETCON_set_timeout(WININET_NETCONNECTION *connection, BOOL send, int value);
-int sock_get_error(int);
+#define sock_get_error(x) WSAGetLastError()
 
 extern void URLCacheContainers_CreateDefaults(void);
 extern void URLCacheContainers_DeleteAll(void);
diff --git a/reactos/dll/win32/wininet/netconnection.c b/reactos/dll/win32/wininet/netconnection.c
index 5aa647a7a49..176163f49f1 100644
--- a/reactos/dll/win32/wininet/netconnection.c
+++ b/reactos/dll/win32/wininet/netconnection.c
@@ -513,6 +513,7 @@ BOOL NETCON_connected(WININET_NETCONNECTION *connection)
         return TRUE;
 }
 
+#if 0
 /* translate a unix error code into a winsock one */
 int sock_get_error( int err )
 {
@@ -579,6 +580,7 @@ int sock_get_error( int err )
 #endif
     return err;
 }
+#endif
 
 /******************************************************************************
  * NETCON_create