diff --git a/ui-ngx/src/app/modules/home/components/widget/lib/flot-widget.ts b/ui-ngx/src/app/modules/home/components/widget/lib/flot-widget.ts
index 846c6b8331..2c46864388 100644
--- a/ui-ngx/src/app/modules/home/components/widget/lib/flot-widget.ts
+++ b/ui-ngx/src/app/modules/home/components/widget/lib/flot-widget.ts
@@ -206,8 +206,8 @@ export class TbFlot {
 
       if (this.settings.yaxis) {
         this.yaxis.font.color = this.settings.yaxis.color || this.yaxis.font.color;
-        this.yaxis.min = isDefined(this.settings.yaxis.min) ? this.settings.yaxis.min : null;
-        this.yaxis.max = isDefined(this.settings.yaxis.max) ? this.settings.yaxis.max : null;
+        this.yaxis.min = isNumber(this.settings.yaxis.min) ? this.settings.yaxis.min : null;
+        this.yaxis.max = isNumber(this.settings.yaxis.max) ? this.settings.yaxis.max : null;
         this.yaxis.label = this.utils.customTranslation(this.settings.yaxis.title, this.settings.yaxis.title) || null;
         this.yaxis.labelFont.color = this.yaxis.font.color;
         this.yaxis.labelFont.size = this.yaxis.font.size + 2;
@@ -895,8 +895,8 @@ export class TbFlot {
       tickSize = yaxis.tickSize;
     }
     const position = keySettings.axisPosition && keySettings.axisPosition.length ? keySettings.axisPosition : 'left';
-    const min = isDefined(keySettings.axisMin) ? keySettings.axisMin : yaxis.min;
-    const max = isDefined(keySettings.axisMax) ? keySettings.axisMax : yaxis.max;
+    const min = isNumber(keySettings.axisMin) ? keySettings.axisMin : yaxis.min;
+    const max = isNumber(keySettings.axisMax) ? keySettings.axisMax : yaxis.max;
     yaxis.label = label;
     yaxis.min = min;
     yaxis.max = max;