diff --git a/src/Controls/src/Core/RadioButton/RadioButton.cs b/src/Controls/src/Core/RadioButton/RadioButton.cs
index 6a83884c2984..553d00ac2b10 100644
--- a/src/Controls/src/Core/RadioButton/RadioButton.cs
+++ b/src/Controls/src/Core/RadioButton/RadioButton.cs
@@ -459,7 +459,9 @@ static View BuildDefaultTemplate()
 
 			border.SetBinding(Border.StrokeProperty, static (RadioButton rb) => rb.BorderColor, source: RelativeBindingSource.TemplatedParent);
 			border.SetBinding(Border.StrokeShapeProperty, static (RadioButton rb) => rb.CornerRadius, source: RelativeBindingSource.TemplatedParent, converter: new CornerRadiusToShape());
-			border.SetBinding(Border.StrokeThicknessProperty, static (RadioButton rb) => rb.BorderWidth, source: RelativeBindingSource.TemplatedParent);
+
+			// NonNegativeValueConverter ensures that StrokeThickness remains non-negative as the default value of -1 triggers a CGContextSetLineWidth error on iOS.
+			border.SetBinding(Border.StrokeThicknessProperty, static (RadioButton rb) => rb.BorderWidth, source: RelativeBindingSource.TemplatedParent, converter: new NonNegativeValueConverter());
 
 			var grid = new Grid
 			{
@@ -694,5 +696,18 @@ public object ConvertBack(object value, Type targetType, object parameter, Syste
 				throw new NotImplementedException();
 			}
 		}
+
+		class NonNegativeValueConverter : IValueConverter
+		{
+			public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
+			{
+				return Math.Max(0, (double)value);
+			}
+
+			public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
+			{
+				throw new NotImplementedException();
+			}
+		}
 	}
 }