1 files changed, 7 insertions, 3 deletions
diff --git a/numpy/core/memmap.py b/numpy/core/memmap.py
index d3dbd09fb..c10ca15c9 100644
--- a/numpy/core/memmap.py
+++ b/numpy/core/memmap.py
@@ -77,9 +77,13 @@ class memmap(ndarray):
         return self
 
     def __array_finalize__(self, obj):
-        if obj is not None and not isinstance(obj, memmap):
-            raise ValueError, "Cannot create a memmap array that way"
-        self._mmap = None
+        if obj is not None:
+            if not isinstance(obj, memmap):
+                raise ValueError, "Cannot create a memmap array that way"
+            self._mmap = obj._mmap
+        else:
+            self._mmap = None
+        return
 
     def sync(self):
         self._mmap.flush()