1 files changed, 1 insertions, 1 deletions
diff --git a/zen/file_io.h b/zen/file_io.h
index 8a5e0f7f..827abd9e 100755
--- a/zen/file_io.h
+++ b/zen/file_io.h
@@ -90,7 +90,7 @@ private:
     size_t tryWrite(const void* buffer, size_t bytesToWrite); //throw FileError; may return short! CONTRACT: bytesToWrite > 0
 
     std::vector<char> memBuf_;
-    const IOCallback notifyUnbufferedIO_; //throw X
+    IOCallback notifyUnbufferedIO_; //throw X
 };
 
 //-----------------------------------------------------------------------------------------------