diff --git a/doc/pcre2_substitute.3 b/doc/pcre2_substitute.3
index 887828f..55d58d2 100644
--- a/doc/pcre2_substitute.3
+++ b/doc/pcre2_substitute.3
@@ -1,4 +1,4 @@
-.TH PCRE2_SUBSTITUTE 3 "06 October 2015" "PCRE2 10.21"
+.TH PCRE2_SUBSTITUTE 3 "04 December 2015" "PCRE2 10.21"
 .SH NAME
 PCRE2 - Perl-compatible regular expressions (revised API)
 .SH SYNOPSIS
@@ -58,6 +58,7 @@ The options are:
                               PCRE2_UTF was set at compile time)
   PCRE2_SUBSTITUTE_EXTENDED  Do extended replacement processing
   PCRE2_SUBSTITUTE_GLOBAL    Replace all occurrences in the subject
+  PCRE2_SUBSTITUTE_UNSET_EMPTY  Simple unset insert = empty string 
 .sp
 The function returns the number of substitutions, which may be zero if there
 were no matches. The result can be greater than one only when