diff --git a/extras/tools/bootstrap b/extras/tools/bootstrap
index 56d1b78..f669966 100755
--- a/extras/tools/bootstrap
+++ b/extras/tools/bootstrap
@@ -29,6 +29,11 @@ if ! $1 --version >/dev/null 2>&1
 then
     echo "$1 not found"
     NEEDED="$NEEDED .$1"
+    if [ "$1" = "xz" ] && ! tar PcJ /dev/null >/dev/null 2>&1
+    then
+        echo "tar doesn't support xz (J option)"
+        NEEDED="$NEEDED .tar"
+    fi
 else
     if [ "$1" = "xz" ] && ! tar PcJ /dev/null >/dev/null
     then