diff --git a/Python/initconfig.c b/Python/initconfig.c
index 44250da..998ceb7 100644
--- a/Python/initconfig.c
+++ b/Python/initconfig.c
@@ -24,6 +24,10 @@
 #  endif
 #endif
 
+#ifndef PLATLIBDIR
+#  error "PLATLIBDIR macro must be defined"
+#endif
+
 
 /* --- Command line options --------------------------------------- */
 
@@ -110,6 +114,7 @@
 static const char usage_5[] =
 "PYTHONHOME   : alternate <prefix> directory (or <prefix>%lc<exec_prefix>).\n"
 "               The default module search path uses %s.\n"
+"PYTHONPLATLIBDIR : override sys.platlibdir.\n"
 "PYTHONCASEOK : ignore case in 'import' statements (Windows).\n"
 "PYTHONUTF8: if set to 1, enable the UTF-8 mode.\n"
 "PYTHONIOENCODING: Encoding[:errors] used for stdin/stdout/stderr.\n"
@@ -586,6 +591,7 @@
     CLEAR(config->base_prefix);
     CLEAR(config->exec_prefix);
     CLEAR(config->base_exec_prefix);
+    CLEAR(config->platlibdir);
 
     CLEAR(config->filesystem_encoding);
     CLEAR(config->filesystem_errors);
@@ -822,6 +828,7 @@
     COPY_WSTR_ATTR(base_prefix);
     COPY_WSTR_ATTR(exec_prefix);
     COPY_WSTR_ATTR(base_exec_prefix);
+    COPY_WSTR_ATTR(platlibdir);
 
     COPY_ATTR(site_import);
     COPY_ATTR(bytes_warning);
@@ -925,6 +932,7 @@
     SET_ITEM_WSTR(base_prefix);
     SET_ITEM_WSTR(exec_prefix);
     SET_ITEM_WSTR(base_exec_prefix);
+    SET_ITEM_WSTR(platlibdir);
     SET_ITEM_INT(site_import);
     SET_ITEM_INT(bytes_warning);
     SET_ITEM_INT(inspect);
@@ -1336,6 +1344,14 @@
         }
     }
 
+    if(config->platlibdir == NULL) {
+        status = CONFIG_GET_ENV_DUP(config, &config->platlibdir,
+                                    L"PYTHONPLATLIBDIR", "PYTHONPLATLIBDIR");
+        if (_PyStatus_EXCEPTION(status)) {
+            return status;
+        }
+    }
+
     if (config->use_hash_seed < 0) {
         status = config_init_hash_seed(config);
         if (_PyStatus_EXCEPTION(status)) {
@@ -1731,6 +1747,14 @@
         }
     }
 
+    if(config->platlibdir == NULL) {
+        status = CONFIG_SET_BYTES_STR(config, &config->platlibdir, PLATLIBDIR,
+                                      "PLATLIBDIR macro");
+        if (_PyStatus_EXCEPTION(status)) {
+            return status;
+        }
+    }
+
     if (config->_install_importlib) {
         status = _PyConfig_InitPathConfig(config);
         if (_PyStatus_EXCEPTION(status)) {
@@ -2560,6 +2584,7 @@
         assert(config->exec_prefix != NULL);
         assert(config->base_exec_prefix != NULL);
     }
+    assert(config->platlibdir != NULL);
     assert(config->filesystem_encoding != NULL);
     assert(config->filesystem_errors != NULL);
     assert(config->stdio_encoding != NULL);
@@ -2710,6 +2735,7 @@
     DUMP_SYS(_base_executable);
     DUMP_SYS(base_prefix);
     DUMP_SYS(base_exec_prefix);
+    DUMP_SYS(platlibdir);
     DUMP_SYS(executable);
     DUMP_SYS(prefix);
     DUMP_SYS(exec_prefix);