diff --git a/MagickCore/quantize.c b/MagickCore/quantize.c
index 5a6a9dc..d46b0d4 100644
--- a/MagickCore/quantize.c
+++ b/MagickCore/quantize.c
@@ -516,9 +516,7 @@
     (void) TransformImageColorspace((Image *) image,
       cube_info->quantize_info->colorspace,exception);
   else
-    if ((image->colorspace != GRAYColorspace) &&
-        (IssRGBColorspace(image->colorspace) == MagickFalse) &&
-        (image->colorspace != CMYColorspace))
+    if (IssRGBCompatibleColorspace(image->colorspace) == MagickFalse)
       (void) TransformImageColorspace((Image *) image,sRGBColorspace,exception);
   if (AcquireImageColormap(image,cube_info->colors,exception) == MagickFalse)
     ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
@@ -803,9 +801,7 @@
     (void) TransformImageColorspace((Image *) image,
       cube_info->quantize_info->colorspace,exception);
   else
-    if ((image->colorspace != GRAYColorspace) &&
-        (image->colorspace != CMYColorspace) &&
-        (IssRGBColorspace(image->colorspace) == MagickFalse))
+    if (IssRGBCompatibleColorspace(image->colorspace) == MagickFalse)
       (void) TransformImageColorspace((Image *) image,sRGBColorspace,exception);
   midpoint.red=(MagickRealType) QuantumRange/2.0;
   midpoint.green=(MagickRealType) QuantumRange/2.0;