diff --git a/src/ImageProcessorCore/Formats/Bmp/BmpDecoderCore.cs b/src/ImageProcessorCore/Formats/Bmp/BmpDecoderCore.cs
index d353e5723..3afc2c75d 100644
--- a/src/ImageProcessorCore/Formats/Bmp/BmpDecoderCore.cs
+++ b/src/ImageProcessorCore/Formats/Bmp/BmpDecoderCore.cs
@@ -103,8 +103,8 @@ namespace ImageProcessorCore.Formats
 
                 if (colorMapSize > 0)
                 {
-                    // 255 * 4
-                    if (colorMapSize > 1020)
+                    // 256 * 4
+                    if (colorMapSize > 1024)
                     {
                         throw new ImageFormatException($"Invalid bmp colormap size '{colorMapSize}'");
                     }