diff --git a/packwiz-setup.sh b/packwiz-setup.sh
index c87b12b..5428532 100755
--- a/packwiz-setup.sh
+++ b/packwiz-setup.sh
@@ -104,12 +104,18 @@ BASEURL="${BASEURL%/}"
 
 # Everything the guides need is derivable from the mirror URL, so one -u is
 # usually enough; each piece can still be overridden individually.
-[ -n "$SITE_URL" ] || [ -z "$BASEURL" ] || SITE_URL="$(awk -F/ '{print $1"//"$3}' <<<"$BASEURL")"
+# Strip the last segment off the mirror URL rather than reducing to the origin,
+# so a mirror under a base path keeps it:
+#   https://host/mods                -> https://host
+#   https://host/abdelpakDelta/mods  -> https://host/abdelpakDelta
+[ -n "$SITE_URL" ] || [ -z "$BASEURL" ] || SITE_URL="${BASEURL%/*}"
 SITE_URL="${SITE_URL%/}"
 
 if [ -n "$SITE_URL" ]; then
     [ -n "$PACK_URL" ]    || PACK_URL="$SITE_URL/packs/$slug"
-    [ -n "$SERVER_ADDR" ] || SERVER_ADDR="$(sed -e 's#^[a-z]*://##' -e 's#:.*##' <<<"$SITE_URL")"
+    # Host only: strip scheme, then any path, then any port. Dropping the path
+    # matters once SITE_URL can carry one.
+    [ -n "$SERVER_ADDR" ] || SERVER_ADDR="$(sed -e 's#^[a-z]*://##' -e 's#/.*##' -e 's#:.*##' <<<"$SITE_URL")"
 fi
 PACK_URL="${PACK_URL%/}"