diff --git a/ChangeLog b/ChangeLog
index f696655f..3c41e4d0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,7 @@
   because mmap windows are freed when their regions are freed
 - have a min bytes for mmap windows as well, so we don't make too many tiny
   windows
+- im_disp2Lab() was broken
 
 26/11/09 started 7.20.3
 - updated en_GB.po translation 
diff --git a/libvips/colour/disp.c b/libvips/colour/disp.c
index d19e41d8..74f0eb0e 100644
--- a/libvips/colour/disp.c
+++ b/libvips/colour/disp.c
@@ -2,6 +2,8 @@
  *
  * 28/10/09
  * 	- from colour.c
+ * 14/12/09
+ * 	- oop, im_disp2Lab() was broken
  */
 
 /*
@@ -621,7 +623,7 @@ im_disp2Lab( IMAGE *in, IMAGE *out, struct im_col_display *d )
 
 	if( im_open_local_array( out, t, 1, "im_disp2Lab:1", "p" ) ||
 		im_disp2XYZ( in, t[0], d ) ||
-		im_XYZ2Lab( t[1], out ) )
+		im_XYZ2Lab( t[0], out ) )
 		return( -1 );
 	
 	return( 0 );