diff --git a/Modules/_io/fileio.c b/Modules/_io/fileio.c

index 4a71a57ec0d..2b40ada195a 100644

--- a/Modules/_io/fileio.c

+++ b/Modules/_io/fileio.c

@@ -146,9 +146,15 @@ dircheck(fileio* self, PyObject *nameobj)

 {

 #if defined(HAVE_FSTAT) && defined(S_IFDIR) && defined(EISDIR)

     struct stat buf;

+    int res;

     if (self->fd < 0)

         return 0;

-    if (fstat(self->fd, &buf) == 0 && S_ISDIR(buf.st_mode)) {

+

+    Py_BEGIN_ALLOW_THREADS

+    res = fstat(self->fd, &buf;;

+    Py_END_ALLOW_THREADS

+

+    if (res == 0 && S_ISDIR(buf.st_mode)) {

         errno = EISDIR;

         PyErr_SetFromErrnoWithFilenameObject(PyExc_IOError, nameobj);

         return -1;

@@ -162,17 +168,34 @@ check_fd(int fd)

 {

 #if defined(HAVE_FSTAT)

     struct stat buf;

-    if (!_PyVerify_fd(fd) || (fstat(fd, &buf) < 0 && errno == EBADF)) {

-        PyObject *exc;

-        char *msg = strerror(EBADF);

-        exc = PyObject_CallFunction(PyExc_OSError, "(is)",

-                                    EBADF, msg);

-        PyErr_SetObject(PyExc_OSError, exc);

-        Py_XDECREF(exc);

-        return -1;

+    int res;

+    PyObject *exc;

+    char *msg;

+

+    if (!_PyVerify_fd(fd)) {

+        goto badfd;

     }

-#endif

+

+    Py_BEGIN_ALLOW_THREADS

+    res = fstat(fd, &buf;;

+    Py_END_ALLOW_THREADS

+

+    if (res < 0 && errno == EBADF) {

+        goto badfd;

+    }

+

     return 0;

+

+badfd:

+    msg = strerror(EBADF);

+    exc = PyObject_CallFunction(PyExc_OSError, "(is)",

+                                EBADF, msg);

+    PyErr_SetObject(PyExc_OSError, exc);

+    Py_XDECREF(exc);

+    return -1;

+#else

+    return 0;

+#endif

 }

@@ -519,9 +542,19 @@ new_buffersize(fileio *self, size_t currentsize)

 #ifdef HAVE_FSTAT

     off_t pos, end;

     struct stat st;

-    if (fstat(self->fd, &st) == 0) {

+    int res;

+

+    Py_BEGIN_ALLOW_THREADS

+    res = fstat(self->fd, &st);

+    Py_END_ALLOW_THREADS

+

+    if (res == 0) {

         end = st.st_size;

+

+        Py_BEGIN_ALLOW_THREADS

         pos = lseek(self->fd, 0L, SEEK_CUR);

+        Py_END_ALLOW_THREADS

+

         /* Files claiming a size smaller than SMALLCHUNK may

            actually be streaming pseudo-files. In this case, we

            apply the more aggressive algorithm below.

diff --git a/Objects/fileobject.c b/Objects/fileobject.c

index 2f63c374d1e..8d1c5812f0d 100644

--- a/Objects/fileobject.c

+++ b/Objects/fileobject.c

@@ -121,10 +121,15 @@ dircheck(PyFileObject* f)

 {

 #if defined(HAVE_FSTAT) && defined(S_IFDIR) && defined(EISDIR)

     struct stat buf;

+    int res;

     if (f->f_fp == NULL)

         return f;

-    if (fstat(fileno(f->f_fp), &buf) == 0 &&

-        S_ISDIR(buf.st_mode)) {

+

+    Py_BEGIN_ALLOW_THREADS

+    res = fstat(fileno(f->f_fp), &buf;;

+    Py_END_ALLOW_THREADS

+

+    if (res == 0 && S_ISDIR(buf.st_mode)) {

         char *msg = strerror(EISDIR);

         PyObject *exc = PyObject_CallFunction(PyExc_IOError, "(isO)",

                                               EISDIR, msg, f->f_name);

@@ -1010,7 +1015,13 @@ new_buffersize(PyFileObject *f, size_t currentsize)

 #ifdef HAVE_FSTAT

     off_t pos, end;

     struct stat st;

-    if (fstat(fileno(f->f_fp), &st) == 0) {

+    int res;

+

+    Py_BEGIN_ALLOW_THREADS

+    res = fstat(fileno(f->f_fp), &st);

+    Py_END_ALLOW_THREADS

+

+    if (res == 0) {

         end = st.st_size;

         /* The following is not a bug: we really need to call lseek()

            *and* ftell().  The reason is that some stdio libraries

@@ -1021,7 +1032,11 @@ new_buffersize(PyFileObject *f, size_t currentsize)

            works.  We can't use the lseek() value either, because we

            need to take the amount of buffered data into account.

            (Yet another reason why stdio stinks. :-) */

+

+        Py_BEGIN_ALLOW_THREADS

         pos = lseek(fileno(f->f_fp), 0L, SEEK_CUR);

+        Py_END_ALLOW_THREADS

+

         if (pos >= 0) {

             pos = ftell(f->f_fp);

         }