diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index d0d68c9..5237f14 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -2127,7 +2127,9 @@
             free(wnamebuf);
             return NULL;
         }
+        Py_BEGIN_ALLOW_THREADS
         hFindFile = FindFirstFileW(wnamebuf, &wFileData);
+        Py_END_ALLOW_THREADS
         if (hFindFile == INVALID_HANDLE_VALUE) {
             int error = GetLastError();
             if (error == ERROR_FILE_NOT_FOUND) {
@@ -2197,7 +2199,9 @@
     if ((d = PyList_New(0)) == NULL)
         return NULL;
 
+    Py_BEGIN_ALLOW_THREADS
     hFindFile = FindFirstFile(namebuf, &FileData);
+    Py_END_ALLOW_THREADS
     if (hFindFile == INVALID_HANDLE_VALUE) {
         int error = GetLastError();
         if (error == ERROR_FILE_NOT_FOUND)