diff --git a/kallithea/lib/vcs/backends/hg/inmemory.py b/kallithea/lib/vcs/backends/hg/inmemory.py
--- a/kallithea/lib/vcs/backends/hg/inmemory.py
+++ b/kallithea/lib/vcs/backends/hg/inmemory.py
@@ -57,7 +57,7 @@ class MercurialInMemoryChangeset(BaseInM
                               if not node.is_binary else node.content),
                         islink=False,
                         isexec=node.is_executable,
-                        copied=False)
+                        copysource=False)
 
             # or changed
             for node in self.changed:
@@ -67,7 +67,7 @@ class MercurialInMemoryChangeset(BaseInM
                               if not node.is_binary else node.content),
                         islink=False,
                         isexec=node.is_executable,
-                        copied=False)
+                        copysource=False)
 
             raise RepositoryError("Given path haven't been marked as added,"
                                   "changed or removed (%s)" % path)
diff --git a/kallithea/lib/vcs/utils/hgcompat.py b/kallithea/lib/vcs/utils/hgcompat.py
--- a/kallithea/lib/vcs/utils/hgcompat.py
+++ b/kallithea/lib/vcs/utils/hgcompat.py
@@ -37,3 +37,11 @@ from mercurial.url import httpbasicauthh
 localrepo.localrepository._lfstatuswriters = [lambda *msg, **opts: None]
 # 3.5 7699d3212994 added the invariant that repo.lfstatus must exist before hitting overridearchive
 localrepo.localrepository.lfstatus = False
+
+# Mercurial 5.0 550a172a603b renamed memfilectx argument `copied` to `copysource`
+import inspect
+if inspect.getargspec(memfilectx.__init__).args[7] != 'copysource':
+    assert inspect.getargspec(memfilectx.__init__).args[7] == 'copied', inspect.getargspec(memfilectx.__init__).args
+    __org_memfilectx_ = memfilectx
+    memfilectx = lambda repo, changectx, path, data, islink=False, isexec=False, copysource=None: \
+        __org_memfilectx_(repo, changectx, path, data, islink=islink, isexec=isexec, copied=copysource)