diff --git a/free-gigs b/free-gigs
index 8d8a2d9..dadf7c4 100755
--- a/free-gigs
+++ b/free-gigs
@@ -19,10 +19,11 @@ if free_bytes=$(stat -f --format="%a*%S" "$target" 2>/dev/null); then
     :
 elif free_bytes=$(stat -f "%a*%S" "$target" 2>/dev/null); then
     # BSD/macOS stat
+    # XXX untested
     :
 else
     # BusyBox stat fallback
-    free_bytes=$(stat -f "$target" | awk '/Block size:/ {bs=$3} /Available:/ {av=$2} END {print av*bs}')
+    free_bytes=$(stat -f -c "%a*%S" "$target")
 fi
 
 free_gb=$((free_bytes / factor / factor / factor))