diff -r 2f563908ebc5 Modules/main.c
--- a/Modules/main.c
+++ b/Modules/main.c
@@ -488,58 +488,6 @@ Py_Main(int argc, wchar_t **argv)
         (p = Py_GETENV("PYTHONNOUSERSITE")) && *p != '\0')
         Py_NoUserSiteDirectory = 1;
 
-#ifdef MS_WINDOWS
-    if (!Py_IgnoreEnvironmentFlag && (wp = _wgetenv(L"PYTHONWARNINGS")) &&
-        *wp != L'\0') {
-        wchar_t *buf, *warning;
-
-        buf = (wchar_t *)malloc((wcslen(wp) + 1) * sizeof(wchar_t));
-        if (buf == NULL)
-            Py_FatalError(
-               "not enough memory to copy PYTHONWARNINGS");
-        wcscpy(buf, wp);
-        for (warning = wcstok(buf, L",");
-             warning != NULL;
-             warning = wcstok(NULL, L",")) {
-            PySys_AddWarnOption(warning);
-        }
-        free(buf);
-    }
-#else
-    if ((p = Py_GETENV("PYTHONWARNINGS")) && *p != '\0') {
-        char *buf, *oldloc;
-        PyObject *unicode;
-
-        /* settle for strtok here as there's no one standard
-           C89 wcstok */
-        buf = (char *)malloc(strlen(p) + 1);
-        if (buf == NULL)
-            Py_FatalError(
-               "not enough memory to copy PYTHONWARNINGS");
-        strcpy(buf, p);
-        oldloc = strdup(setlocale(LC_ALL, NULL));
-        setlocale(LC_ALL, "");
-        for (p = strtok(buf, ","); p != NULL; p = strtok(NULL, ",")) {
-#ifdef __APPLE__
-            /* Use utf-8 on Mac OS X */
-            unicode = PyUnicode_FromString(p);
-#else
-            unicode = PyUnicode_DecodeLocale(p, "surrogateescape");
-#endif
-            if (unicode == NULL) {
-                /* ignore errors */
-                PyErr_Clear();
-                continue;
-            }
-            PySys_AddWarnOptionUnicode(unicode);
-            Py_DECREF(unicode);
-        }
-        setlocale(LC_ALL, oldloc);
-        free(oldloc);
-        free(buf);
-    }
-#endif
-
     if (command == NULL && module == NULL && _PyOS_optind < argc &&
         wcscmp(argv[_PyOS_optind], L"-") != 0)
     {
diff -r 2f563908ebc5 Python/pythonrun.c
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -275,6 +275,58 @@ Py_InitializeEx(int install_sigs)
     if ((p = Py_GETENV("PYTHONHASHSEED")) && *p != '\0')
         Py_HashRandomizationFlag = add_flag(Py_HashRandomizationFlag, p);
 
+#ifdef MS_WINDOWS
+    if (!Py_IgnoreEnvironmentFlag && (wp = _wgetenv(L"PYTHONWARNINGS")) &&
+        *wp != L'\0') {
+        wchar_t *buf, *warning;
+
+        buf = (wchar_t *)malloc((wcslen(wp) + 1) * sizeof(wchar_t));
+        if (buf == NULL)
+            Py_FatalError(
+               "not enough memory to copy PYTHONWARNINGS");
+        wcscpy(buf, wp);
+        for (warning = wcstok(buf, L",");
+             warning != NULL;
+             warning = wcstok(NULL, L",")) {
+            PySys_AddWarnOption(warning);
+        }
+        free(buf);
+    }
+#else
+    if ((p = Py_GETENV("PYTHONWARNINGS")) && *p != '\0') {
+        char *buf, *oldloc;
+        PyObject *unicode;
+
+        /* settle for strtok here as there's no one standard
+           C89 wcstok */
+        buf = (char *)malloc(strlen(p) + 1);
+        if (buf == NULL)
+            Py_FatalError(
+               "not enough memory to copy PYTHONWARNINGS");
+        strcpy(buf, p);
+        oldloc = strdup(setlocale(LC_ALL, NULL));
+        setlocale(LC_ALL, "");
+        for (p = strtok(buf, ","); p != NULL; p = strtok(NULL, ",")) {
+#ifdef __APPLE__
+            /* Use utf-8 on Mac OS X */
+            unicode = PyUnicode_FromString(p);
+#else
+            unicode = PyUnicode_DecodeLocale(p, "surrogateescape");
+#endif
+            if (unicode == NULL) {
+                /* ignore errors */
+                PyErr_Clear();
+                continue;
+            }
+            PySys_AddWarnOptionUnicode(unicode);
+            Py_DECREF(unicode);
+        }
+        setlocale(LC_ALL, oldloc);
+        free(oldloc);
+        free(buf);
+    }
+#endif
+
     _PyRandom_Init();
 
     interp = PyInterpreterState_New();