diff --git a/hgext/largefiles/lfutil.py b/hgext/largefiles/lfutil.py
--- a/hgext/largefiles/lfutil.py
+++ b/hgext/largefiles/lfutil.py
@@ -245,9 +245,9 @@ def copyfromcache(repo, hash, filename):
         return False
     return True
 
-def copytostore(repo, rev, file, uploaded=False):
+def copytostore(repo, revorctx, file, uploaded=False):
     wvfs = repo.wvfs
-    hash = readstandin(repo, file, rev)
+    hash = readstandin(repo, file, revorctx)
     if instore(repo, hash):
         return
     if wvfs.exists(file):
@@ -263,7 +263,7 @@ def copyalltostore(repo, node):
     for filename in ctx.files():
         realfile = splitstandin(filename)
         if realfile is not None and filename in ctx.manifest():
-            copytostore(repo, ctx.node(), realfile)
+            copytostore(repo, ctx, realfile)
 
 def copytostoreabsolute(repo, file, hash):
     if inusercache(repo.ui, hash):
@@ -485,6 +485,11 @@ def markcommitted(orig, ctx, node):
     lfdirstate.write()
 
     # As part of committing, copy all of the largefiles into the cache.
+    #
+    # Using "node" instead of "ctx" implies additional "repo[node]"
+    # lookup while copyalltostore(), but can omit redundant check for
+    # files comming from the 2nd parent, which should exist in store
+    # at merging.
     copyalltostore(repo, node)
 
 def getlfilestoupdate(oldstandins, newstandins):
diff --git a/hgext/largefiles/overrides.py b/hgext/largefiles/overrides.py
--- a/hgext/largefiles/overrides.py
+++ b/hgext/largefiles/overrides.py
@@ -1354,7 +1354,7 @@ def overridecat(orig, ui, repo, file1, *
                     data = repo.wwritedata(f, data)
                 fp.write(data)
             else:
-                hash = lfutil.readstandin(repo, lf, ctx.rev())
+                hash = lfutil.readstandin(repo, lf, ctx)
                 if not lfutil.inusercache(repo.ui, hash):
                     store = storefactory.openstore(repo)
                     success, missing = store.get([(lf, hash)])
@@ -1405,7 +1405,7 @@ def mergeupdate(orig, repo, node, branch
             lfutil.writestandin(repo, standin, lfhash,
                                 lfutil.getexecutable(lfileabs))
             if (standin in pctx and
-                lfhash == lfutil.readstandin(repo, lfile, '.')):
+                lfhash == lfutil.readstandin(repo, lfile, pctx)):
                 oldclean.add(lfile)
         for lfile in s.added:
             lfutil.updatestandin(repo, lfutil.standin(lfile))