diff --git a/docs/install.md b/docs/install.md
index 14d813c7..66d423f1 100644
--- a/docs/install.md
+++ b/docs/install.md
@@ -21,7 +21,7 @@ git clone https://github.com/jotech/gapseq && cd gapseq
 ## MacOS
 using [homebrew](https://brew.sh)
 ```
-brew install coreutils binutils git glpk blast bedtools r brewsci/bio/barrnap
+brew install coreutils binutils git glpk blast bedtools r brewsci/bio/barrnap grep
 R -e 'install.packages(c("data.table", "stringr", "sybil", "getopt", "reshape2", "doParallel", "foreach", "R.utils", "stringi", "glpkAPI"))'
 R -e 'if (!requireNamespace("BiocManager", quietly = TRUE)) install.packages("BiocManager"); BiocManager::install("Biostrings")'
 git clone https://github.com/jotech/gapseq && cd gapseq