diff --git a/extras/tools/bootstrap b/extras/tools/bootstrap
index 56d1b78..5b4b989 100755
--- a/extras/tools/bootstrap
+++ b/extras/tools/bootstrap
@@ -49,6 +49,11 @@ else
         NEEDED="$NEEDED .$1"
     fi
 fi
+if [ "$1" = "xz" ] && ! tar PcJ /dev/null >/dev/null 2>&1
+    then
+        echo "tar doesn't support xz (J option)"
+        NEEDED="$NEEDED .tar"
+fi
 }

 check autoconf 2.67