diff --git a/src/normal.c b/src/normal.c
index 74a5efe..fe1a182 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -5477,6 +5477,14 @@
 #ifdef FEAT_SYN_HL
 	/* Clear all syntax states to force resyncing. */
 	syn_stack_free_all(curwin->w_s);
+# ifdef FEAT_RELTIME
+	{
+	    win_T *wp;
+
+	    FOR_ALL_WINDOWS(wp)
+		wp->w_s->b_syn_slow = FALSE;
+	}
+# endif
 #endif
 	redraw_later(CLEAR);
     }