diff --git a/libvips/foreign/tiff2vips.c b/libvips/foreign/tiff2vips.c
index 8d909722..d6cb3836 100644
--- a/libvips/foreign/tiff2vips.c
+++ b/libvips/foreign/tiff2vips.c
@@ -939,7 +939,7 @@ rtiff_greyscale_line( Rtiff *rtiff,
 		rtiff->header.photometric_interpretation;
 	VipsBandFormat format = rtiff_guess_format( rtiff ); 
 
-	/* Swapping black and white doesn't work for the signed formats.
+	/* Swapping black and white doesn't make sense for the signed formats.
 	 */
 	gboolean invert = 
 		photometric_interpretation == PHOTOMETRIC_MINISWHITE &&