diff --git a/src/Magick.NET/Colors/MagickColor.cs b/src/Magick.NET/Colors/MagickColor.cs
index 3379d69c64..a246a2b727 100644
--- a/src/Magick.NET/Colors/MagickColor.cs
+++ b/src/Magick.NET/Colors/MagickColor.cs
@@ -257,7 +257,7 @@ private MagickColor(NativeMagickColor instance)
         if (!color.IsCmyk)
             return new MagickColor(red, green, blue, color.A);
 
-        var key = (QuantumType)percentage.Multiply((double)color.K);
+        var key = Quantum.Convert(percentage.Multiply((double)color.K));
 
         return new MagickColor(red, green, blue, key, color.A);
     }