diff --git a/hgext/mq.py b/hgext/mq.py
--- a/hgext/mq.py
+++ b/hgext/mq.py
@@ -1302,7 +1302,7 @@ class queue(object):
                     except OSError, e:
                         if e.errno != errno.ENOENT:
                             raise
-                    repo.dirstate.forget(f)
+                    repo.dirstate.drop(f)
                 for f in m + r:
                     fctx = ctx[f]
                     repo.wwrite(f, fctx.data(), fctx.flags())
@@ -1480,7 +1480,7 @@ class queue(object):
                 for f in mm:
                     repo.dirstate.normallookup(f)
                 for f in forget:
-                    repo.dirstate.forget(f)
+                    repo.dirstate.drop(f)
 
                 if not msg:
                     if not ph.message:
@@ -2617,7 +2617,7 @@ def rename(ui, repo, patch, name=None, *
         wlock = r.wlock()
         try:
             if r.dirstate[patch] == 'a':
-                r.dirstate.forget(patch)
+                r.dirstate.drop(patch)
                 r.dirstate.add(name)
             else:
                 if r.dirstate[name] == 'r':
diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -4264,7 +4264,7 @@ def revert(ui, repo, *pats, **opts):
             audit_path = scmutil.pathauditor(repo.root)
             for f in remove[0]:
                 if repo.dirstate[f] == 'a':
-                    repo.dirstate.forget(f)
+                    repo.dirstate.drop(f)
                     continue
                 audit_path(f)
                 try:
diff --git a/mercurial/context.py b/mercurial/context.py
--- a/mercurial/context.py
+++ b/mercurial/context.py
@@ -842,7 +842,7 @@ class workingctx(changectx):
                 if self._repo.dirstate[f] != 'a':
                     self._repo.ui.warn(_("%s not added!\n") % f)
                 else:
-                    self._repo.dirstate.forget(f)
+                    self._repo.dirstate.drop(f)
         finally:
             wlock.release()
 
@@ -863,7 +863,7 @@ class workingctx(changectx):
                             raise
             for f in list:
                 if self._repo.dirstate[f] == 'a':
-                    self._repo.dirstate.forget(f)
+                    self._repo.dirstate.drop(f)
                 elif f not in self._repo.dirstate:
                     self._repo.ui.warn(_("%s not tracked!\n") % f)
                 else:
diff --git a/mercurial/dirstate.py b/mercurial/dirstate.py
--- a/mercurial/dirstate.py
+++ b/mercurial/dirstate.py
@@ -365,14 +365,11 @@ class dirstate(object):
         if f in self._copymap:
             del self._copymap[f]
 
-    def forget(self, f):
-        '''Forget a file.'''
+    def drop(self, f):
+        '''Drop a file from the dirstate'''
         self._dirty = True
-        try:
-            self._droppath(f)
-            del self._map[f]
-        except KeyError:
-            self._ui.warn(_("not in dirstate: %s\n") % f)
+        self._droppath(f)
+        del self._map[f]
 
     def _normalize(self, path, isknown):
         normed = os.path.normcase(path)
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -1037,7 +1037,7 @@ class localrepository(repo.repository):
             for f in changes[0] + changes[1]:
                 self.dirstate.normal(f)
             for f in changes[2]:
-                self.dirstate.forget(f)
+                self.dirstate.drop(f)
             self.dirstate.setparents(ret)
             ms.reset()
         finally:
diff --git a/mercurial/merge.py b/mercurial/merge.py
--- a/mercurial/merge.py
+++ b/mercurial/merge.py
@@ -390,12 +390,12 @@ def recordupdates(repo, action, branchme
             if branchmerge:
                 repo.dirstate.remove(f)
             else:
-                repo.dirstate.forget(f)
+                repo.dirstate.drop(f)
         elif m == "a": # re-add
             if not branchmerge:
                 repo.dirstate.add(f)
         elif m == "f": # forget
-            repo.dirstate.forget(f)
+            repo.dirstate.drop(f)
         elif m == "e": # exec change
             repo.dirstate.normallookup(f)
         elif m == "g": # get
@@ -425,7 +425,7 @@ def recordupdates(repo, action, branchme
                 if f2 == fd: # file not locally copied/moved
                     repo.dirstate.normallookup(fd)
                 if move:
-                    repo.dirstate.forget(f)
+                    repo.dirstate.drop(f)
         elif m == "d": # directory rename
             f2, fd, flag = a[2:]
             if not f2 and f not in repo.dirstate:
@@ -441,7 +441,7 @@ def recordupdates(repo, action, branchme
             else:
                 repo.dirstate.normal(fd)
                 if f:
-                    repo.dirstate.forget(f)
+                    repo.dirstate.drop(f)
 
 def update(repo, node, branchmerge, force, partial, ancestor=None):
     """