diff --git a/parallel_xz.sh b/parallel_xz.sh
index bc08a548d..65621501c 100755
--- a/parallel_xz.sh
+++ b/parallel_xz.sh
@@ -16,6 +16,11 @@ while test "$#" != 0; do
 	shift
 done
 
+#This seems to cause problems with large numbers
+if (( $procgroup > 8 )); then
+	procgroup=8
+fi
+
 # If told to use only one cpu:
 test "$procgroup" || exec xargs -r xz
 test "$procgroup" = 1 && exec xargs -r xz