diff --git a/ChangeLog b/ChangeLog
index 069a8d63..9fe97e87 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,7 @@
 - foreign memory buffer images did not have the right dhint, broke
   command-line falsecolour on sequential images
 - support many Radiance readers active at once
+- add secret "rgbjpeg" flag to vips_tiffsave() to help IIP
 
 19/1/14 started 7.38.1
 - bump soname, thanks benjamin
diff --git a/libvips/foreign/tiff.h b/libvips/foreign/tiff.h
index af8a308f..5090df53 100644
--- a/libvips/foreign/tiff.h
+++ b/libvips/foreign/tiff.h
@@ -47,7 +47,8 @@ int vips__tiff_write( VipsImage *in, const char *filename,
 	gboolean pyramid,
 	gboolean squash,
 	VipsForeignTiffResunit resunit, double xres, double yres,
-	gboolean bigtiff );
+	gboolean bigtiff,
+	gboolean rgbjpeg );
 
 int vips__tiff_read( const char *filename, VipsImage *out, int page, 
 	gboolean readbehind );
diff --git a/libvips/foreign/tiffsave.c b/libvips/foreign/tiffsave.c
index aa20c34a..14f71a92 100644
--- a/libvips/foreign/tiffsave.c
+++ b/libvips/foreign/tiffsave.c
@@ -4,6 +4,8 @@
  * 	- wrap a class around the tiff writer
  * 17/3/12
  * 	- argh xres/yres macro was wrong
+ * 26/1/14
+ * 	- add rgbjpeg flag
  */
 
 /*
@@ -75,6 +77,7 @@ typedef struct _VipsForeignSaveTiff {
 	double xres;
 	double yres;
 	gboolean bigtiff;
+	gboolean rgbjpeg;
 } VipsForeignSaveTiff;
 
 typedef VipsForeignSaveClass VipsForeignSaveTiffClass;
@@ -123,7 +126,8 @@ vips_foreign_save_tiff_build( VipsObject *object )
 		tiff->pyramid,
 		tiff->squash,
 		tiff->resunit, tiff->xres, tiff->yres,
-		tiff->bigtiff ) )
+		tiff->bigtiff,
+		tiff->rgbjpeg ) )
 		return( -1 );
 
 	return( 0 );
@@ -249,6 +253,13 @@ vips_foreign_save_tiff_class_init( VipsForeignSaveTiffClass *class )
 		VIPS_ARGUMENT_OPTIONAL_INPUT,
 		G_STRUCT_OFFSET( VipsForeignSaveTiff, bigtiff ),
 		FALSE );
+
+	VIPS_ARG_BOOL( class, "rgbjpeg", 20, 
+		_( "RGB JPEG" ),
+		_( "Output RGB JPEG rather than YCbCr" ),
+		VIPS_ARGUMENT_OPTIONAL_INPUT | VIPS_ARGUMENT_DEPRECATED, 
+		G_STRUCT_OFFSET( VipsForeignSaveTiff, rgbjpeg ),
+		FALSE );
 }
 
 static void
diff --git a/libvips/foreign/vips2tiff.c b/libvips/foreign/vips2tiff.c
index 73081cda..0294f9ba 100644
--- a/libvips/foreign/vips2tiff.c
+++ b/libvips/foreign/vips2tiff.c
@@ -136,6 +136,8 @@
  * 24/9/13
  * 	- support many more vips formats, eg. complex, 32-bit int, any number
  * 	  of bands, etc., see the tiff loader
+ * 26/1/14
+ * 	- add RGB as well as YCbCr write
  */
 
 /*
@@ -261,6 +263,7 @@ typedef struct tiff_write {
         float yres;                    	/* Resolution in Y */
 	char *icc_profile;		/* Profile to embed */
 	int bigtiff;			/* True for bigtiff write */
+	int rgbjpeg;			/* True for RGB not YCbCr */
 
 	GMutex *write_lock;		/* Lock TIFF*() calls with this */
 } TiffWrite;
@@ -529,7 +532,8 @@ write_tiff_header( TiffWrite *tw, TIFF *tif, int width, int height )
 			}
 			else if( tw->compression == COMPRESSION_JPEG &&
 				tw->im->Bands == 3 &&
-				tw->im->BandFmt == VIPS_FORMAT_UCHAR ) { 
+				tw->im->BandFmt == VIPS_FORMAT_UCHAR &&
+				!tw->rgbjpeg ) { 
 				/* This signals to libjpeg that it can do
 				 * YCbCr chrominance subsampling from RGB, not
 				 * that we will supply the image as YCbCr.
@@ -1291,7 +1295,8 @@ make_tiff_write( VipsImage *im, const char *filename,
 	gboolean pyramid,
 	gboolean squash,
 	VipsForeignTiffResunit resunit, double xres, double yres,
-	gboolean bigtiff )
+	gboolean bigtiff,
+	gboolean rgbjpeg )
 {
 	TiffWrite *tw;
 
@@ -1313,6 +1318,7 @@ make_tiff_write( VipsImage *im, const char *filename,
 	tw->onebit = squash;
 	tw->icc_profile = profile;
 	tw->bigtiff = bigtiff;
+	tw->rgbjpeg = rgbjpeg;
 	tw->write_lock = NULL;
 
 	tw->resunit = get_resunit( resunit );
@@ -1531,7 +1537,8 @@ vips__tiff_write( VipsImage *in, const char *filename,
 	gboolean pyramid,
 	gboolean squash,
 	VipsForeignTiffResunit resunit, double xres, double yres,
-	gboolean bigtiff )
+	gboolean bigtiff,
+	gboolean rgbjpeg )
 {
 	TiffWrite *tw;
 	int res;
@@ -1553,7 +1560,7 @@ vips__tiff_write( VipsImage *in, const char *filename,
 	if( !(tw = make_tiff_write( in, filename,
 		compression, Q, predictor, profile,
 		tile, tile_width, tile_height, pyramid, squash,
-		resunit, xres, yres, bigtiff )) )
+		resunit, xres, yres, bigtiff, rgbjpeg )) )
 		return( -1 );
 	if( tw->pyramid ) {
 		if( !(tw->bname = vips__temp_name( "%s.tif" )) ||
diff --git a/libvips/iofuncs/buffer.c b/libvips/iofuncs/buffer.c
index 52602061..62299a3f 100644
--- a/libvips/iofuncs/buffer.c
+++ b/libvips/iofuncs/buffer.c
@@ -276,7 +276,6 @@ vips_buffer_undone( VipsBuffer *buffer )
 {
 	if( buffer->done ) {
 		VipsBufferCache *cache = buffer->cache;
-		VipsBufferThread *buffer_thread = cache->buffer_thread;
 
 #ifdef DEBUG_VERBOSE
 		printf( "vips_buffer_undone: thread %p removing "
@@ -285,9 +284,9 @@ vips_buffer_undone( VipsBuffer *buffer )
 #endif /*DEBUG_VERBOSE*/
 
 		g_assert( cache->thread == g_thread_self() );
-		g_assert( buffer_thread->thread == cache->thread );
+		g_assert( cache->buffer_thread->thread == cache->thread );
 		g_assert( g_slist_find( cache->buffers, buffer ) );
-		g_assert( buffer_thread == buffer_thread_get() );
+		g_assert( cache->buffer_thread == buffer_thread_get() );
 
 		cache->buffers = g_slist_remove( cache->buffers, buffer );