diff --git a/README.md b/README.md
index 61230f5..aee025a 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@ Compared to SEQUEST-HT/Percolator (using a publicly available HEK293 data set PX
 
 ## Installation of PD nodes
 
-The MSFragger node can be used with Thermo Scientific Proteome Discoverer versions 2.2 (not yet tested with 2.1 2.3). 
+The MSFragger node can be used with Thermo Scientific Proteome Discoverer versions 2.2 (not yet tested with v2.1 and v2.3). 
 
 Please follow the steps below for the installation: