diff --git a/src/structs.h b/src/structs.h
index d79b225..c7aa8f2 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -1797,6 +1797,9 @@
     hashtab_T	b_keywtab;		/* syntax keywords hash table */
     hashtab_T	b_keywtab_ic;		/* idem, ignore case */
     int		b_syn_error;		/* TRUE when error occurred in HL */
+# ifdef FEAT_RELTIME
+    int		b_syn_slow;		/* TRUE when 'redrawtime' reached */
+# endif
     int		b_syn_ic;		/* ignore case for :syn cmds */
     int		b_syn_spell;		/* SYNSPL_ values */
     garray_T	b_syn_patterns;		/* table for syntax patterns */