diff --git a/CTSkullStripping/README.md b/CTSkullStripping/README.md
index 64e3966..49c1fc4 100644
--- a/CTSkullStripping/README.md
+++ b/CTSkullStripping/README.md
@@ -8,7 +8,7 @@ Overview
 Prerequisites
 -------------
 
-- SegmentEditorExtraEffects extension is installed.
+- SegmentEditorExtraEffects and SurfaceWrapSolidify extensions are installed.
 - Head CT image is loaded.
 
 Recommended workflow