diff -Naur Python-3.5.2-orig/Modules/getpath.c Python-3.5.2/Modules/getpath.c
--- Python-3.5.2-orig/Modules/getpath.c	2016-07-12 14:22:01.929300700 +0300
+++ Python-3.5.2/Modules/getpath.c	2016-07-12 14:22:02.242800700 +0300
@@ -848,6 +848,32 @@
     else
         wcsncpy(exec_prefix, _exec_prefix, MAXPATHLEN);
 
+#ifdef MS_WINDOWS
+    if (_path) {
+        wchar_t *module_path, *new_path;
+        /* Add path of executable/dll to system path. This
+         * is so that the correct tcl??.dll and tk??.dll get used. */
+        path_buffer = Py_DecodeLocale(_path, NULL);
+        module_path = dllpath[0] ? dllpath : progpath;
+        new_path = (wchar_t *)alloca(sizeof(wchar_t)*(wcslen(L"PATH=")+wcslen(module_path)+1+wcslen(path_buffer)+1));
+        if (new_path) {
+            wchar_t *slashes, *end;
+            wcscpy(new_path, L"PATH=");
+            wcscat(new_path, module_path);
+            slashes = wcschr(new_path, L'/');
+            while (slashes) {
+                *slashes = L'\\';
+                slashes = wcschr( slashes+1, L'/' );
+            }
+            end = wcsrchr(new_path, L'\\') ? wcsrchr(new_path, L'\\') : new_path + wcslen(new_path);
+            end[0] = L';';
+            end[1] = L'\0';
+            wcscat(new_path, path_buffer);
+            _wputenv(new_path);
+            PyMem_RawFree(path_buffer);
+        }
+    }
+#endif
     PyMem_RawFree(_pythonpath);
     PyMem_RawFree(_prefix);
     PyMem_RawFree(_exec_prefix);