diff --git a/hgext/largefiles/lfutil.py b/hgext/largefiles/lfutil.py
--- a/hgext/largefiles/lfutil.py
+++ b/hgext/largefiles/lfutil.py
@@ -10,7 +10,6 @@
 
 import os
 import platform
-import shutil
 import stat
 import copy
 
@@ -207,7 +206,15 @@ def copyfromcache(repo, hash, filename):
     util.makedirs(os.path.dirname(repo.wjoin(filename)))
     # The write may fail before the file is fully written, but we
     # don't use atomic writes in the working copy.
-    shutil.copy(path, repo.wjoin(filename))
+    dest = repo.wjoin(filename)
+    with open(path, 'rb') as srcfd:
+        with open(dest, 'wb') as destfd:
+            gothash = copyandhash(srcfd, destfd)
+    if gothash != hash:
+        repo.ui.warn(_('%s: data corruption in %s with hash %s\n')
+                     % (filename, path, gothash))
+        util.unlink(dest)
+        return False
     return True
 
 def copytostore(repo, rev, file, uploaded=False):
diff --git a/tests/test-largefiles-cache.t b/tests/test-largefiles-cache.t
--- a/tests/test-largefiles-cache.t
+++ b/tests/test-largefiles-cache.t
@@ -191,13 +191,12 @@ Inject corruption into the largefiles st
   e2fb5f2139d086ded2cb600d5a91a196e76bf020
   $ mv .hg/largefiles/e2fb5f2139d086ded2cb600d5a91a196e76bf020 ..
   $ echo corruption > .hg/largefiles/e2fb5f2139d086ded2cb600d5a91a196e76bf020
-(the following update will put the corrupted file into the working directory
-where it will show up as a change)
   $ hg up -C
   getting changed largefiles
-  1 largefiles updated, 0 removed
+  large: data corruption in $TESTTMP/src/.hg/largefiles/e2fb5f2139d086ded2cb600d5a91a196e76bf020 with hash 6a7bb2556144babe3899b25e5428123735bb1e27
+  0 largefiles updated, 0 removed
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg st
-  M large
+  ! large
   ? z
   $ rm .hg/largefiles/e2fb5f2139d086ded2cb600d5a91a196e76bf020