diff --git a/libvips/conversion/sequential.c b/libvips/conversion/sequential.c
index ac76e7e6..77139489 100644
--- a/libvips/conversion/sequential.c
+++ b/libvips/conversion/sequential.c
@@ -109,50 +109,44 @@ vips_sequential_generate( VipsRegion *or,
 		vips_diag( "VipsSequential", 
 			"request for %d lines, starting at line %d", 
 			r->height, r->top );
-retry:
 
 	g_mutex_lock( sequential->lock );
 
 	VIPS_DEBUG_MSG( "thread %p has lock ...\n", g_thread_self() ); 
 
 	if( r->top > sequential->y_pos ) {
-		/* This is for stuff in the future, stall.
+		VipsRect area;
+
+		/* This is for stuff in the future, read from the current
+		 * point to the start of this new chunk.
 		 */
-		VIPS_DEBUG_MSG( "thread %p stalling ...\n", g_thread_self() ); 
-		g_cond_wait( sequential->ready, sequential->lock );
-		VIPS_DEBUG_MSG( "thread %p awake again, retrying ...\n", 
-			g_thread_self() ); 
-		g_mutex_unlock( sequential->lock );
-		goto retry;
+		area.left = 0;
+		area.top = sequential->y_pos;
+		area.width = 1;
+		area.height = r->top - sequential->y_pos;
+
+		if( vips_region_prepare( ir, &area ) ) {
+			g_mutex_unlock( sequential->lock );
+			return( -1 );
+		}
+
+		sequential->y_pos = VIPS_RECT_BOTTOM( &area );
 	}
 
 	/* This is a request for old or present pixels -- serve from cache.
-	 * This may trigger further, sequential reads.
+	 * This may trigger further reads.
 	 */
-	VIPS_DEBUG_MSG( "thread %p reading ...\n", g_thread_self() ); 
 	if( vips_region_prepare( ir, r ) ||
 		vips_region_region( or, ir, r, r->left, r->top ) ) {
-		VIPS_DEBUG_MSG( "thread %p unlocking ...\n", g_thread_self() ); 
 		g_mutex_unlock( sequential->lock );
 		return( -1 );
 	}
 
 	if( VIPS_RECT_BOTTOM( r ) > sequential->y_pos ) {
-		/* This request has moved the read point. Update it, and wake 
-		 * up all stalled threads for a retry.
-		 */
 		sequential->y_pos = VIPS_RECT_BOTTOM( r );
 
-		VIPS_DEBUG_MSG( "thread %p updating y_pos to %d and "
-			"waking stalled\n", 
-			g_thread_self(),
-			sequential->y_pos ); 
-
-		g_cond_broadcast( sequential->ready );
 	}
 
-	VIPS_DEBUG_MSG( "thread %p unlocking ...\n", g_thread_self() ); 
-
 	g_mutex_unlock( sequential->lock );
 
 	return( 0 );