diff --git a/BUILDING.md b/BUILDING.md
index 59588a263..e6c4bf71d 100644
--- a/BUILDING.md
+++ b/BUILDING.md
@@ -81,7 +81,7 @@ installed before you can build it.
 - setuptools
 - pygobject
 - gtk3 (>= 3.12)
-- python (>= 2.7.4)
+- python (>= 3.8)
 - swig (>= 3)
 - numpy
 - librsvg2 (and its svg gdk-pixbuf loader)
diff --git a/gui/brushmanager.py b/gui/brushmanager.py
index f31efc0cf..6e4d1f7d2 100644
--- a/gui/brushmanager.py
+++ b/gui/brushmanager.py
@@ -860,8 +860,12 @@ def export_group(self, group, filename):
 
         """
         brushes = self.get_group_brushes(group)
-        order_conf = b"Group: %s\n" % utf8(group)
-        with zipfile.ZipFile(filename, mode="w") as zf:
+        order_conf = b'Group: %s\n' % utf8(group)
+        with zipfile.ZipFile(
+            filename,
+            mode='w',
+            strict_timestamps=False,
+        ) as zf:
             for brush in brushes:
                 prefix = brush._get_fileprefix()
                 zf.write(prefix + ".myb", brush.name + ".myb")