diff --git a/R/readNWISsite.r b/R/readNWISsite.r
index cd29868abd294ad8e2061d24b820f881eef0ef3b..dfe0a60df9105b2ea5a4b51ce81b99d59a887e49 100644
--- a/R/readNWISsite.r
+++ b/R/readNWISsite.r
@@ -66,7 +66,7 @@
 readNWISsite <- function(siteNumbers){
   
   siteNumber <- paste(siteNumbers,collapse=",")
-  urlSitefile <- paste("http://waterservices.usgs.gov/nwis/site/?format=rdb&siteOutput=Expanded&sites=",siteNumber,sep = "")
+  urlSitefile <- paste0("http://waterservices.usgs.gov/nwis/site/?format=rdb&siteOutput=Expanded&sites=",siteNumber)
   
   data <- importRDB1(urlSitefile,asDateTime=FALSE)