diff -Naur Python-3.7.0-orig/Lib/site.py Python-3.7.0/Lib/site.py
--- Python-3.7.0-orig/Lib/site.py	2018-06-27 06:07:35.000000000 +0300
+++ Python-3.7.0/Lib/site.py	2018-07-12 10:21:38.157583100 +0300
@@ -250,7 +250,8 @@
     def joinuser(*args):
         return os.path.expanduser(os.path.join(*args))
 
-    if os.name == "nt":
+    from sysconfig import _POSIX_BUILD
+    if os.name == "nt" and not _POSIX_BUILD:
         base = os.environ.get("APPDATA") or "~"
         return joinuser(base, "Python")
 
@@ -265,7 +266,8 @@
 def _get_path(userbase):
     version = sys.version_info
 
-    if os.name == 'nt':
+    from sysconfig import _POSIX_BUILD
+    if sys.platform == 'win32' and not _POSIX_BUILD:
         return f'{userbase}\\Python{version[0]}{version[1]}\\site-packages'
 
     if sys.platform == 'darwin' and sys._framework:
@@ -328,12 +330,13 @@
     if prefixes is None:
         prefixes = PREFIXES
 
+    from sysconfig import _POSIX_BUILD
     for prefix in prefixes:
         if not prefix or prefix in seen:
             continue
         seen.add(prefix)
 
-        if os.sep == '/':
+        if _POSIX_BUILD:
             sitepackages.append(os.path.join(prefix, "lib",
                                         "python%d.%d" % sys.version_info[:2],
                                         "site-packages"))