diff --git a/mercurial/patch.py b/mercurial/patch.py
--- a/mercurial/patch.py
+++ b/mercurial/patch.py
@@ -1166,6 +1166,8 @@ def internalpatch(patchobj, ui, strip, c
     finally:
         if cwd:
             os.chdir(curdir)
+        if fp != patchobj:
+            fp.close()
     if ret < 0:
         raise PatchError
     return ret > 0