diff --git a/mercurial/dirstate.py b/mercurial/dirstate.py
--- a/mercurial/dirstate.py
+++ b/mercurial/dirstate.py
@@ -627,7 +627,7 @@ class dirstate(object):
     def _writedirstate(self, st):
         # use the modification time of the newly created temporary file as the
         # filesystem's notion of 'now'
-        now = util.fstat(st).st_mtime
+        now = util.statmtimesec(util.fstat(st)) & _rangemask
         st.write(parsers.pack_dirstate(self._map, self._copymap, self._pl, now))
         st.close()
         self._lastnormaltime = 0
diff --git a/mercurial/parsers.c b/mercurial/parsers.c
--- a/mercurial/parsers.c
+++ b/mercurial/parsers.c
@@ -551,9 +551,9 @@ static PyObject *pack_dirstate(PyObject 
 	Py_ssize_t nbytes, pos, l;
 	PyObject *k, *v = NULL, *pn;
 	char *p, *s;
-	double now;
+	int now;
 
-	if (!PyArg_ParseTuple(args, "O!O!Od:pack_dirstate",
+	if (!PyArg_ParseTuple(args, "O!O!Oi:pack_dirstate",
 			      &PyDict_Type, &map, &PyDict_Type, &copymap,
 			      &pl, &now))
 		return NULL;
@@ -622,7 +622,7 @@ static PyObject *pack_dirstate(PyObject 
 		mode = tuple->mode;
 		size = tuple->size;
 		mtime = tuple->mtime;
-		if (state == 'n' && mtime == (uint32_t)now) {
+		if (state == 'n' && mtime == now) {
 			/* See pure/parsers.py:pack_dirstate for why we do
 			 * this. */
 			mtime = -1;
diff --git a/tests/fakedirstatewritetime.py b/tests/fakedirstatewritetime.py
--- a/tests/fakedirstatewritetime.py
+++ b/tests/fakedirstatewritetime.py
@@ -31,8 +31,7 @@ def fakewrite(ui, func):
 
     # parsing 'fakenow' in YYYYmmddHHMM format makes comparison between
     # 'fakenow' value and 'touch -t YYYYmmddHHMM' argument easy
-    timestamp = util.parsedate(fakenow, ['%Y%m%d%H%M'])[0]
-    fakenow = float(timestamp)
+    fakenow = util.parsedate(fakenow, ['%Y%m%d%H%M'])[0]
 
     orig_pack_dirstate = parsers.pack_dirstate
     wrapper = lambda *args: pack_dirstate(fakenow, orig_pack_dirstate, *args)