diff --git a/README.md b/README.md
index e6b01aa..eac9d22 100644
--- a/README.md
+++ b/README.md
@@ -43,4 +43,6 @@ kv.get('my_key') # returns True.
 kv.delete('my_key')
 ~~~
 
-***Warning:*** **Be sure to keep flush_on_exit set to true or manually flush when destroying the kv instance (such as by exiting your program) to avoid losing data.**
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+***Warning:*** **Be sure to keep flush_on_exit set to true or manually flush when destroying the kv instance (such as by exiting your program) to avoid losing data.**
+
+***Warning:*** **flush_on_exit should be set to false when using the same file from multiple threads or processes, otherwise you will lose data.**
\ No newline at end of file