diff -Naur Python-3.6.5-orig/Modules/_cursesmodule.c Python-3.6.5/Modules/_cursesmodule.c
--- Python-3.6.5-orig/Modules/_cursesmodule.c	2018-03-28 12:19:31.000000000 +0300
+++ Python-3.6.5/Modules/_cursesmodule.c	2018-04-16 09:54:27.146677000 +0300
@@ -125,6 +125,10 @@
 #include <langinfo.h>
 #endif
 
+#ifdef __MINGW32__
+#include <windows.h>
+#endif
+
 #if !defined(HAVE_NCURSES_H) && (defined(sgi) || defined(__sun) || defined(SCO5))
 #define STRICT_SYSV_CURSES       /* Don't use ncurses extensions */
 typedef chtype attr_t;           /* No attr_t type is available */
@@ -1748,10 +1752,14 @@
     /* We have to simulate this by writing to a temporary FILE*,
        then reading back, then writing to the argument stream. */
     char fn[100];
+#ifndef MS_WINDOWS
     int fd = -1;
+#endif
     FILE *fp = NULL;
     PyObject *res = NULL;
 
+#ifndef MS_WINDOWS
+/* Even on unix /tmp may not exist and the program must prefer $TMPDIR ! */
     strcpy(fn, "/tmp/py.curses.putwin.XXXXXX");
     fd = mkstemp(fn);
     if (fd < 0)
@@ -1759,6 +1767,14 @@
     if (_Py_set_inheritable(fd, 0, NULL) < 0)
         goto exit;
     fp = fdopen(fd, "wb+");
+#else
+    strcpy(fn, "py.curses.putwin.XXXXXX");
+    _mktemp(fn);
+    if (*fn == 0)
+        return PyErr_SetFromErrnoWithFilename(PyExc_IOError, fn);
+    fp = fopen(fn, "wb+");
+#endif
+
     if (fp == NULL) {
         PyErr_SetFromErrnoWithFilename(PyExc_IOError, fn);
         goto exit;
@@ -1783,8 +1799,10 @@
 exit:
     if (fp != NULL)
         fclose(fp);
+    #ifndef MS_WINDOWS
     else if (fd != -1)
         close(fd);
+    #endif
     remove(fn);
     return res;
 }
@@ -2324,7 +2342,9 @@
 PyCurses_GetWin(PyCursesWindowObject *self, PyObject *stream)
 {
     char fn[100];
+#ifndef MS_WINDOWS
     int fd = -1;
+#endif
     FILE *fp = NULL;
     PyObject *data;
     size_t datalen;
@@ -2334,6 +2354,8 @@
 
     PyCursesInitialised;
 
+#ifndef MS_WINDOWS
+/* Even on unix /tmp may not exist and the program must prefer $TMPDIR ! */
     strcpy(fn, "/tmp/py.curses.getwin.XXXXXX");
     fd = mkstemp(fn);
     if (fd < 0)
@@ -2341,6 +2363,13 @@
     if (_Py_set_inheritable(fd, 0, NULL) < 0)
         goto error;
     fp = fdopen(fd, "wb+");
+#else
+    strcpy(fn, "py.curses.getwin.XXXXXX");
+    _mktemp(fn);
+    if (*fn == 0)
+        return PyErr_SetFromErrnoWithFilename(PyExc_IOError, fn);
+    fp = fopen(fn, "wb+");
+#endif
     if (fp == NULL) {
         PyErr_SetFromErrnoWithFilename(PyExc_IOError, fn);
         goto error;
@@ -2375,8 +2404,10 @@
 error:
     if (fp != NULL)
         fclose(fp);
+    #ifndef MS_WINDOWS
     else if (fd != -1)
         close(fd);
+    #endif
     remove(fn);
     return res;
 }