--- a/hgext/evolve.py	Tue Oct 28 23:18:56 2014 -0400
+++ b/hgext/evolve.py	Tue Oct 28 18:06:28 2014 -0700
@@ -1987,6 +1987,9 @@
         rev = None
         if opts.get('rev'):
             rev = scmutil.revsingle(repo, opts.get('rev'))
+            ctx = repo[None]
+            if ctx.p1() == rev or ctx.p2() == rev:
+                raise util.Abort(_("cannot uncommit to parent changeset"))
 
         # Recommit the filtered changeset
         tr = repo.transaction('uncommit')