diff --git a/src/diff.c b/src/diff.c
index 82be8b9..fec3382 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -602,7 +602,7 @@
     for (wp = firstwin; wp != NULL; wp = wp->w_next)
 	if (wp->w_p_diff)
 	{
-	    redraw_win_later(wp, NOT_VALID);
+	    redraw_win_later(wp, SOME_VALID);
 #ifdef FEAT_FOLDING
 	    if (dofold && foldmethodIsDiff(wp))
 		foldUpdateAll(wp);
diff --git a/src/proto/syntax.pro b/src/proto/syntax.pro
index d0a0049..1204b89 100644
--- a/src/proto/syntax.pro
+++ b/src/proto/syntax.pro
@@ -25,6 +25,7 @@
 void clear_hl_tables __ARGS((void));
 int hl_combine_attr __ARGS((int char_attr, int prim_attr));
 attrentry_T *syn_gui_attr2entry __ARGS((int attr));
+int syn_attr2attr __ARGS((int attr));
 attrentry_T *syn_term_attr2entry __ARGS((int attr));
 attrentry_T *syn_cterm_attr2entry __ARGS((int attr));
 char_u *highlight_has_attr __ARGS((int id, int flag, int modec));