diff --git a/r.snippets.txt b/r.snippets.txt
index bd3fffc..e4f5246 100644
--- a/r.snippets.txt
+++ b/r.snippets.txt
@@ -29,7 +29,7 @@ snippet DTrmColumn
 	
 snippet changeColumnType
 	# define columns to change
-	changeCols  <- c("${1:col1}, ${1:col2}") 
+	changeCols  <- c("${1:col1}", "${1:col2}") 
 	${3:DT}[,(changeCols):= lapply(.SD, as.factor), .SDcols = changeCols]
 
 snippet mat