diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -2310,11 +2310,16 @@
 	}
 	if (!PyArg_ParseTuple(args, "et:listdir", Py_FileSystemDefaultEncoding, &name))
 		return NULL;
-	if ((dirp = opendir(name)) == NULL) {
+	Py_BEGIN_ALLOW_THREADS
+	dirp = opendir(name);
+	Py_END_ALLOW_THREADS
+	if (dirp == NULL) {
 		return posix_error_with_allocated_filename(name);
 	}
 	if ((d = PyList_New(0)) == NULL) {
+		Py_BEGIN_ALLOW_THREADS
 		closedir(dirp);
+		Py_END_ALLOW_THREADS
 		PyMem_Free(name);
 		return NULL;
 	}
@@ -2327,7 +2332,9 @@
 			if (errno == 0) {
 				break;
 			} else {
+				Py_BEGIN_ALLOW_THREADS
 				closedir(dirp);
+				Py_END_ALLOW_THREADS
 				Py_DECREF(d);
 				return posix_error_with_allocated_filename(name);
 			}
@@ -2368,7 +2375,9 @@
 		}
 		Py_DECREF(v);
 	}
+	Py_BEGIN_ALLOW_THREADS
 	closedir(dirp);
+	Py_END_ALLOW_THREADS
 	PyMem_Free(name);
 
 	return d;