diff --git a/README.md b/README.md
index eda79b8..52ad54c 100644
--- a/README.md
+++ b/README.md
@@ -37,7 +37,7 @@ Used to validate mutect2 workflow.
 - False Positive VCF files and its index with summary  
      
 ### Software version requirements :
-- GATK4 or later 
+- GATK4.1.1.0 
 
 Cromwell version support 
 - Successfully tested on v36