diff --git a/Modules/parsermodule.c b/Modules/parsermodule.c
index 6c4a6ad..5764c24 100644
--- a/Modules/parsermodule.c
+++ b/Modules/parsermodule.c
@@ -3269,7 +3269,7 @@
      * If this fails, the import of this module will fail because an
      * exception will be raised here; should we clear the exception?
      */
-    copyreg = PyImport_ImportModule("copy_reg");
+    copyreg = PyImport_ImportModuleNoBlock("copy_reg");
     if (copyreg != NULL) {
         PyObject *func, *pickler;