diff --git a/programs/README.md b/programs/README.md
index baf90e88f..afbebaa16 100644
--- a/programs/README.md
+++ b/programs/README.md
@@ -176,6 +176,7 @@ Benchmark arguments :
 Using environment variables to set compression/decompression parameters has security implications. Therefore,
 we intentionally restrict its usage. Currently, only `ZSTD_CLEVEL` is supported for setting compression level.
 If the value of `ZSTD_CLEVEL` is not a valid integer, it will be ignored with a warning message.
+Note that command line options will override corresponding environment variable settings.
 
 #### Long distance matching mode
 The long distance matching mode, enabled with `--long`, is designed to improve