diff --git a/tuskar_ui/infrastructure/overview/forms.py b/tuskar_ui/infrastructure/overview/forms.py
index 8336028ae..110d94945 100644
--- a/tuskar_ui/infrastructure/overview/forms.py
+++ b/tuskar_ui/infrastructure/overview/forms.py
@@ -136,7 +136,10 @@ class EditPlan(horizon.forms.SelfHandlingForm):
         for role in plan.role_list:
             field = django.forms.IntegerField(
                 label=role.name,
-                widget=tuskar_ui.forms.NumberPickerInput,
+                widget=tuskar_ui.forms.NumberPickerInput(attrs={
+                    'min': 1 if role.name in ('controller', 'compute') else 0,
+                    'step': 2 if role.name == 'controller' else 1,
+                }),
                 initial=plan.get_role_node_count(role),
                 required=False
             )
diff --git a/tuskar_ui/infrastructure/static/infrastructure/js/tuskar.number_picker.js b/tuskar_ui/infrastructure/static/infrastructure/js/tuskar.number_picker.js
index 498081567..dee7bc4a0 100644
--- a/tuskar_ui/infrastructure/static/infrastructure/js/tuskar.number_picker.js
+++ b/tuskar_ui/infrastructure/static/infrastructure/js/tuskar.number_picker.js
@@ -16,13 +16,23 @@ tuskar.number_picker = (function () {
             if ($this.attr('readonly')) {
                 $this.parent().addClass('readonly');
             }
-            $this.next('a.arrow-right').click(function () {
-                $this.val((+$this.val()) + 1);
+            function change(step) {
+                var value = +$this.val();
+                var maximum = +$this.attr('max');
+                var minimum = +$this.attr('min');
+                value += step;
+                if (!isNaN(maximum)) { value = Math.min(maximum, value); }
+                if (!isNaN(minimum)) { value = Math.max(minimum, value); }
+                $this.val(value);
                 $this.trigger('change');
+            }
+            $this.next('a.arrow-right').click(function () {
+                var step = +($this.attr('step') || 1);
+                change(step);
             });
             $this.prev('a.arrow-left').click(function () {
-                $this.val(Math.max(0, (+$this.val()) - 1));
-                $this.trigger('change');
+                var step = -($this.attr('step') || 1);
+                change(step);
             });
         });
     };