diff --git a/beakerx/beakerx/plot/chart.py b/beakerx/beakerx/plot/chart.py
index 354a8d73cf..0ef69bdbee 100644
--- a/beakerx/beakerx/plot/chart.py
+++ b/beakerx/beakerx/plot/chart.py
@@ -442,11 +442,15 @@ def __init__(self, **kwargs):
     
     def add(self, item):
         super(NanoPlot, self).add(item)
-        converted = []
         for l in self.chart.graphics_list:
+            convertedx = []
+            convertedy = []
             for x in l.x:
-                converted.append(str(x))
-            l.x = converted
+                convertedx.append(str(x))
+            l.x = convertedx
+            for y in l.y:
+                convertedy.append(str(y))
+            l.y = convertedy
         self.model = self.chart.transform()
         return self
 
diff --git a/js/notebook/src/plot/plotUtils.js b/js/notebook/src/plot/plotUtils.js
index 6ca548b025..a952ee3f93 100644
--- a/js/notebook/src/plot/plotUtils.js
+++ b/js/notebook/src/plot/plotUtils.js
@@ -218,10 +218,12 @@ define([
 
       var self = this;
       var increaseRange = function(value) {
-        return self.plus(value, self.div((value || 1), 10));
+        var v = self.eq(value, 0) ? 1 : value || 1;
+        return self.plus(value, self.div(v, 10));
       };
       var decreaseRange = function(value){
-        return self.minus(value, self.div((value || 1), 10));
+        var v = self.eq(value, 0) ? 1 : value || 1;
+        return self.minus(value, self.div(v, 10));
       };
 
       if (this.eq(datarange.xl, datarange.xr)) {