diff --git a/src/option.h b/src/option.h
index 71ffa90..ada0c0b 100644
--- a/src/option.h
+++ b/src/option.h
@@ -613,6 +613,7 @@
 #ifdef FEAT_MZSCHEME
 EXTERN long	p_mzq;		/* 'mzquantum */
 #endif
+EXTERN char_u	*p_opfunc;	/* 'operatorfunc' */
 EXTERN char_u	*p_para;	/* 'paragraphs' */
 EXTERN int	p_paste;	/* 'paste' */
 EXTERN char_u	*p_pt;		/* 'pastetoggle' */