diff --git a/src/indent.c b/src/indent.c
index 3c38b4e..1858ecf 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -871,6 +871,7 @@
     p = wp->w_p_briopt;
     while (*p != NUL)
     {
+	// Note: Keep this in sync with p_briopt_values
 	if (STRNCMP(p, "shift:", 6) == 0
 		 && ((p[6] == '-' && VIM_ISDIGIT(p[7])) || VIM_ISDIGIT(p[6])))
 	{