diff --git a/mercurial/cext/parsers.c b/mercurial/cext/parsers.c
--- a/mercurial/cext/parsers.c
+++ b/mercurial/cext/parsers.c
@@ -66,6 +66,7 @@
 	int mtime_s;
 	int mtime_ns;
 	PyObject *parentfiledata;
+	PyObject *mtime;
 	PyObject *fallback_exec;
 	PyObject *fallback_symlink;
 	static char *keywords_name[] = {
@@ -118,10 +119,18 @@
 	}
 
 	if (parentfiledata != Py_None) {
-		if (!PyArg_ParseTuple(parentfiledata, "ii(ii)", &mode, &size,
-		                      &mtime_s, &mtime_ns)) {
+		if (!PyArg_ParseTuple(parentfiledata, "iiO", &mode, &size,
+		                      &mtime)) {
 			return NULL;
 		}
+		if (mtime != Py_None) {
+			if (!PyArg_ParseTuple(mtime, "ii", &mtime_s,
+			                      &mtime_ns)) {
+				return NULL;
+			}
+		} else {
+			has_meaningful_mtime = 0;
+		}
 	} else {
 		has_meaningful_data = 0;
 		has_meaningful_mtime = 0;
@@ -475,10 +484,19 @@
                                          PyObject *args)
 {
 	int size, mode, mtime_s, mtime_ns;
-	if (!PyArg_ParseTuple(args, "ii(ii)", &mode, &size, &mtime_s,
-	                      &mtime_ns)) {
+	PyObject *mtime;
+	mtime_s = 0;
+	mtime_ns = 0;
+	if (!PyArg_ParseTuple(args, "iiO", &mode, &size, &mtime)) {
 		return NULL;
 	}
+	if (mtime != Py_None) {
+		if (!PyArg_ParseTuple(mtime, "ii", &mtime_s, &mtime_ns)) {
+			return NULL;
+		}
+	} else {
+		self->flags &= ~dirstate_flag_has_mtime;
+	}
 	self->flags = dirstate_flag_wc_tracked | dirstate_flag_p1_tracked |
 	              dirstate_flag_has_meaningful_data |
 	              dirstate_flag_has_mtime;
diff --git a/mercurial/dirstate.py b/mercurial/dirstate.py
--- a/mercurial/dirstate.py
+++ b/mercurial/dirstate.py
@@ -611,6 +611,7 @@
         )
         if (
             parentfiledata is not None
+            and parentfiledata[2] is not None
             and parentfiledata[2] > self._lastnormaltime
         ):
             # Remember the most recent modification timeslot for status(),
diff --git a/mercurial/pure/parsers.py b/mercurial/pure/parsers.py
--- a/mercurial/pure/parsers.py
+++ b/mercurial/pure/parsers.py
@@ -130,6 +130,8 @@
         if parentfiledata is None:
             has_meaningful_mtime = False
             has_meaningful_data = False
+        elif parentfiledata[2] is None:
+            has_meaningful_mtime = False
         if has_meaningful_data:
             self._mode = parentfiledata[0]
             self._size = parentfiledata[1]
diff --git a/rust/hg-cpython/src/dirstate/item.rs b/rust/hg-cpython/src/dirstate/item.rs
--- a/rust/hg-cpython/src/dirstate/item.rs
+++ b/rust/hg-cpython/src/dirstate/item.rs
@@ -23,7 +23,7 @@
         p2_info: bool = false,
         has_meaningful_data: bool = true,
         has_meaningful_mtime: bool = true,
-        parentfiledata: Option<(u32, u32, (u32, u32))> = None,
+        parentfiledata: Option<(u32, u32, Option<(u32, u32)>)> = None,
         fallback_exec: Option<bool> = None,
         fallback_symlink: Option<bool> = None,
 
@@ -35,7 +35,9 @@
                 mode_size_opt = Some((mode, size))
             }
             if has_meaningful_mtime {
-                mtime_opt = Some(timestamp(py, mtime)?)
+                if let Some(m) = mtime {
+                    mtime_opt = Some(timestamp(py, m)?);
+                }
             }
         }
         let entry = DirstateEntry::from_v2_data(