diff --git a/filter_subdomains.sh b/filter_subdomains.sh
index 08ad5c1..d576b8c 100755
--- a/filter_subdomains.sh
+++ b/filter_subdomains.sh
@@ -19,6 +19,7 @@ sort -u temp/all_toblock.list > dist/firstparty-trackers.txt
     echo "# Generation version: eulaurarien $(git describe --tags)"
     echo "# Number of source websites: $(wc -l temp/all_websites.list | cut -d' ' -f1)"
     echo "# Number of source subdomains: $(wc -l temp/all_subdomains.list | cut -d' ' -f1)"
+    echo "# Number of known trackers : $(python -c 'import regexes; print(len(regexes.REGEXES))')"
     echo "# Number of blocked subdomains: $(wc -l dist/firstparty-trackers.txt | cut -d' ' -f1)"
     echo
     cat dist/firstparty-trackers.txt | while read host;