diff --git a/coders/pnm.c b/coders/pnm.c
index d4e9242..5fa8918 100644
--- a/coders/pnm.c
+++ b/coders/pnm.c
@@ -1564,7 +1564,8 @@
       }
     if (format != '7')
       {
-        if (IssRGBColorspace(image->colorspace) == MagickFalse)
+        if ((IssRGBColorspace(image->colorspace) == MagickFalse) &&
+            (IsImageGray(image,exception) == MagickFalse))
           (void) TransformImageColorspace(image,sRGBColorspace,exception);
         (void) FormatLocaleString(buffer,MaxTextExtent,"%.20g %.20g\n",
           (double) image->columns,(double) image->rows);