diff --git a/src/main/java/com/trifork/bitcask/BitCask.java b/src/main/java/com/trifork/bitcask/BitCask.java
index fdeedb1..c4c435f 100644
--- a/src/main/java/com/trifork/bitcask/BitCask.java
+++ b/src/main/java/com/trifork/bitcask/BitCask.java
@@ -105,7 +105,12 @@ public void put(ByteString key, ByteString value) throws IOException {
 			write_lock.write_activefile(nwf);
 
 			write_file = nwf;
-			read_files.put(last_write_file.filename, last_write_file);
+			if (read_files.get(last_write_file.filename) == null)
+                        {
+                           read_files.put(last_write_file.filename, last_write_file);
+                        } else {
+                           last_write_file.close();
+                        }
 			break;
 		}