diff --git a/src/option.h b/src/option.h
index 5e8574d..78560c6 100644
--- a/src/option.h
+++ b/src/option.h
@@ -826,6 +826,7 @@
 #endif
 EXTERN char_u	*p_udir;	/* 'undodir' */
 EXTERN long	p_ul;		/* 'undolevels' */
+EXTERN long	p_ur;		/* 'undoreload' */
 EXTERN long	p_uc;		/* 'updatecount' */
 EXTERN long	p_ut;		/* 'updatetime' */
 #if defined(FEAT_WINDOWS) || defined(FEAT_FOLDING)