diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index edf72480..501483c4 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -837,6 +837,13 @@ vips_foreign_load_build( VipsObject *object )
 		build( object ) )
 		return( -1 );
 
+	if( load->sequential ) {
+		vips_warn( class->nickname, "%s", 
+			_( "ignoring deprecated \"sequential\" mode" ) ); 
+		vips_warn( class->nickname, "%s", 
+			_( "please use \"access\" instead" ) ); 
+	}
+
 	g_object_set( object, "out", vips_image_new(), NULL ); 
 
 	vips_image_set_string( load->out, 
diff --git a/tools/vipsthumbnail.c b/tools/vipsthumbnail.c
index c5359883..4c618705 100644
--- a/tools/vipsthumbnail.c
+++ b/tools/vipsthumbnail.c
@@ -261,7 +261,7 @@ thumbnail_open( VipsObject *thumbnail, const char *filename )
 				jpegshrink ); 
 
 			if( vips_foreign_load( filename, &im,
-				"sequential", TRUE,
+				"access", VIPS_ACCESS_SEQUENTIAL,
 				"shrink", jpegshrink,
 				NULL ) )
 				return( NULL );
@@ -271,7 +271,7 @@ thumbnail_open( VipsObject *thumbnail, const char *filename )
 		/* All other formats.
 		 */
 		if( vips_foreign_load( filename, &im,
-			"sequential", TRUE,
+			"access", VIPS_ACCESS_SEQUENTIAL,
 			NULL ) )
 			return( NULL );
 	}