diff --git a/src/syntax.c b/src/syntax.c
index 29b6888..a43f4a6 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -509,7 +509,9 @@
      * Also do this when a change was made, the current state may be invalid
      * then.
      */
-    if (syn_block != wp->w_s || changedtick != syn_buf->b_changedtick)
+    if (syn_block != wp->w_s
+	    || syn_buf != wp->w_buffer
+	    || changedtick != syn_buf->b_changedtick)
     {
 	invalidate_current_state();
 	syn_buf = wp->w_buffer;