diff --git a/binarycpython/utils/grid.py b/binarycpython/utils/grid.py
index f53e01b87aa55e504468f23a0723cb4888fdfc69..703ce4aaa579a8d495968082fc39c949b1e58ad4 100644
--- a/binarycpython/utils/grid.py
+++ b/binarycpython/utils/grid.py
@@ -4238,7 +4238,7 @@ eccentricity3=0
             "{system_number}/{total_starcount}{modulo} {complete:5.1f}% complete {hours:02d}:{minutes:02d}:{seconds:02d} ETA={eta:7.1f}{units} tpr={tpr:2.2e} ETF={etf} mem:{mem_use:.1f}MB".format(
                 system_number = system_number,
                 total_starcount = self.grid_options["_total_starcount"],
-                complete=(100.0*system_number)/(1.0*self.grid_options["_total_starcount"]),
+                complete=(100.0*system_number)/(1.0*self.grid_options["_total_starcount"]) if self.grid_options["_total_starcount"] else -1,
                 modulo = modulo,
                 hours = localtime.tm_hour,
                 minutes = localtime.tm_min,