diff -r 5c962163f77a -r e8f7e4c53537 hgext/evolve.py
--- a/hgext/evolve.py	Mon Sep 14 13:23:43 2015 -0700
+++ b/hgext/evolve.py	Mon Sep 14 13:48:34 2015 -0700
@@ -2004,11 +2004,15 @@
         shouldmove = opts.get('move_bookmark') and bm is not None
         ret = hg.update(repo, p.rev())
         if not ret:
-            if shouldmove:
-                repo._bookmarks[bm] = p.node()
-                repo._bookmarks.write()
-            else:
-                bmdeactivate(repo)
+            wlock = repo.wlock()
+            try:
+                if shouldmove:
+                    repo._bookmarks[bm] = p.node()
+                    repo._bookmarks.write()
+                else:
+                    bmdeactivate(repo)
+            finally:
+                wlock.release()
         displayer.show(p)
         return 0
     else:
@@ -2048,11 +2052,15 @@
         shouldmove = opts.get('move_bookmark') and bm is not None
         ret = hg.update(repo, c.rev())
         if not ret:
-            if shouldmove:
-                repo._bookmarks[bm] = c.node()
-                repo._bookmarks.write()
-            else:
-                bmdeactivate(repo)
+            wlock = repo.wlock()
+            try:
+                if shouldmove:
+                    repo._bookmarks[bm] = c.node()
+                    repo._bookmarks.write()
+                else:
+                    bmdeactivate(repo)
+            finally:
+                wlock.release()
         displayer.show(c)
         result = 0
     elif children: