diff --git a/Modules/_winapi.c b/Modules/_winapi.c
index 4b9455e..6c99394 100644
--- a/Modules/_winapi.c
+++ b/Modules/_winapi.c
@@ -1280,6 +1280,7 @@
     WINAPI_CONSTANT(F_DWORD, CREATE_NEW_CONSOLE);
     WINAPI_CONSTANT(F_DWORD, CREATE_NEW_PROCESS_GROUP);
     WINAPI_CONSTANT(F_DWORD, DUPLICATE_SAME_ACCESS);
+    WINAPI_CONSTANT(F_DWORD, DUPLICATE_CLOSE_SOURCE);
     WINAPI_CONSTANT(F_DWORD, ERROR_ALREADY_EXISTS);
     WINAPI_CONSTANT(F_DWORD, ERROR_BROKEN_PIPE);
     WINAPI_CONSTANT(F_DWORD, ERROR_IO_PENDING);
@@ -1298,6 +1299,8 @@
     WINAPI_CONSTANT(F_DWORD, ERROR_SEM_TIMEOUT);
     WINAPI_CONSTANT(F_DWORD, FILE_FLAG_FIRST_PIPE_INSTANCE);
     WINAPI_CONSTANT(F_DWORD, FILE_FLAG_OVERLAPPED);
+    WINAPI_CONSTANT(F_DWORD, FILE_GENERIC_READ);
+    WINAPI_CONSTANT(F_DWORD, FILE_GENERIC_WRITE);
     WINAPI_CONSTANT(F_DWORD, GENERIC_READ);
     WINAPI_CONSTANT(F_DWORD, GENERIC_WRITE);
     WINAPI_CONSTANT(F_DWORD, INFINITE);
@@ -1310,6 +1313,7 @@
     WINAPI_CONSTANT(F_DWORD, PIPE_UNLIMITED_INSTANCES);
     WINAPI_CONSTANT(F_DWORD, PIPE_WAIT);
     WINAPI_CONSTANT(F_DWORD, PROCESS_ALL_ACCESS);
+    WINAPI_CONSTANT(F_DWORD, PROCESS_DUP_HANDLE);
     WINAPI_CONSTANT(F_DWORD, STARTF_USESHOWWINDOW);
     WINAPI_CONSTANT(F_DWORD, STARTF_USESTDHANDLES);
     WINAPI_CONSTANT(F_DWORD, STD_INPUT_HANDLE);