diff --git chart.module chart.module
index 55d1601..8ba58e2 100644
--- chart.module
+++ chart.module
@@ -419,7 +419,7 @@ function _chart_adjust_resolution($chart_id, &$data, $max_value = NULL) {
     if ($max[$chart_id] > $resoluton) {
       $divider = round($max[$chart_id] / $resoluton, 1);
     }
-    else {
+    elseif ($max[$chart_id] > 0) {
       $multiplier = round($resoluton / $max[$chart_id], 1);
     }