diff --git a/README.md b/README.md
index 04d6e0c..a4cc9db 100644
--- a/README.md
+++ b/README.md
@@ -43,6 +43,8 @@ chopper -q 10 -l 500 -i reads.fastq > filtered_reads.fastq
 chopper -q 10 -l 500 -i reads.fastq.gz | gzip > filtered_reads.fastq.gz
 ```
 
+Note that the tool may be substantially slower in the third example above, and piping while decompressing is recommended (as in the first example). 
+
 ## CITATION
 
 If you use this tool, please consider citing our [publication](https://academic.oup.com/bioinformatics/article/39/5/btad311/7160911).