diff --git a/blacklist.sh b/blacklist.sh
index 7667fec..1f1f96e 100755
--- a/blacklist.sh
+++ b/blacklist.sh
@@ -72,7 +72,7 @@ for url in $urls; do
     headers=$(mktemp)
 
     # download the blocklist
-    set_name=$(echo "$url" | awk -F/ '{print substring($3,0,21);}') # set name is derived from source URL hostname
+    set_name=$(echo "$url" | awk -F/ '{print substr($3,0,21);}') # set name is derived from source URL hostname
     curl -v -s ${COMPRESS_OPT} -k "$url" >"${unsorted_blocklist}" 2>"${headers}"
 
     # this is required for blocklist.de that sends compressed content if asked for it or not