diff --git a/hgext/histedit.py b/hgext/histedit.py
--- a/hgext/histedit.py
+++ b/hgext/histedit.py
@@ -593,7 +593,8 @@ def between(repo, old, new, keep):
     When keep is false, the specified set can't have children."""
     ctxs = list(repo.set('%n::%n', old, new))
     if ctxs and not keep:
-        if repo.revs('(%ld::) - (%ld + hidden())', ctxs, ctxs):
+        if (not obsolete._enabled and
+            repo.revs('(%ld::) - (%ld + hidden())', ctxs, ctxs)):
             raise util.Abort(_('cannot edit history that would orphan nodes'))
         root = ctxs[0] # list is already sorted by repo.set
         if not root.phase():
diff --git a/tests/test-histedit-obsolete.t b/tests/test-histedit-obsolete.t
--- a/tests/test-histedit-obsolete.t
+++ b/tests/test-histedit-obsolete.t
@@ -141,3 +141,15 @@ Check that histedit respect phases
   $ hg histedit -r '.~2'
   abort: cannot edit immutable changeset: cb9a9f314b8b
   [255]
+
+
++Test ui.prevent-unstable option
++------------------------------------
+
+  $ hg up '.^'
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ hg phase --force --draft .
+  $ hg log -r 'children(.)'
+  9:7c044e3e33a9 f (no-eol)
+  $ hg histedit -r '.'
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved