diff --git a/mercurial/cext/manifest.c b/mercurial/cext/manifest.c
--- a/mercurial/cext/manifest.c
+++ b/mercurial/cext/manifest.c
@@ -262,7 +262,7 @@
 #endif
 
 static PyTypeObject lazymanifestEntriesIterator = {
-	PyVarObject_HEAD_INIT(NULL, 0)
+	PyVarObject_HEAD_INIT(NULL, 0) /* header */
 	"parsers.lazymanifest.entriesiterator", /*tp_name */
 	sizeof(lmIter),                  /*tp_basicsize */
 	0,                               /*tp_itemsize */
@@ -310,7 +310,7 @@
 #endif
 
 static PyTypeObject lazymanifestKeysIterator = {
-	PyVarObject_HEAD_INIT(NULL, 0)
+	PyVarObject_HEAD_INIT(NULL, 0) /* header */
 	"parsers.lazymanifest.keysiterator", /*tp_name */
 	sizeof(lmIter),                  /*tp_basicsize */
 	0,                               /*tp_itemsize */
@@ -890,7 +890,7 @@
 #endif
 
 static PyTypeObject lazymanifestType = {
-	PyVarObject_HEAD_INIT(NULL, 0)
+	PyVarObject_HEAD_INIT(NULL, 0) /* header */
 	"parsers.lazymanifest",                           /* tp_name */
 	sizeof(lazymanifest),                             /* tp_basicsize */
 	0,                                                /* tp_itemsize */
diff --git a/mercurial/cext/osutil.c b/mercurial/cext/osutil.c
--- a/mercurial/cext/osutil.c
+++ b/mercurial/cext/osutil.c
@@ -121,7 +121,7 @@
 }
 
 static PyTypeObject listdir_stat_type = {
-	PyVarObject_HEAD_INIT(NULL, 0)
+	PyVarObject_HEAD_INIT(NULL, 0) /* header */
 	"osutil.stat",             /*tp_name*/
 	sizeof(struct listdir_stat), /*tp_basicsize*/
 	0,                         /*tp_itemsize*/
diff --git a/mercurial/cext/parsers.c b/mercurial/cext/parsers.c
--- a/mercurial/cext/parsers.c
+++ b/mercurial/cext/parsers.c
@@ -195,7 +195,7 @@
 };
 
 PyTypeObject dirstateTupleType = {
-	PyVarObject_HEAD_INIT(NULL, 0)
+	PyVarObject_HEAD_INIT(NULL, 0) /* header */
 	"dirstate_tuple",          /* tp_name */
 	sizeof(dirstateTupleObject),/* tp_basicsize */
 	0,                         /* tp_itemsize */
diff --git a/mercurial/cext/revlog.c b/mercurial/cext/revlog.c
--- a/mercurial/cext/revlog.c
+++ b/mercurial/cext/revlog.c
@@ -1991,7 +1991,7 @@
 };
 
 static PyTypeObject indexType = {
-	PyVarObject_HEAD_INIT(NULL, 0)
+	PyVarObject_HEAD_INIT(NULL, 0) /* header */
 	"parsers.index",           /* tp_name */
 	sizeof(indexObject),       /* tp_basicsize */
 	0,                         /* tp_itemsize */