diff --git a/ChangeLog b/ChangeLog
index e29dea769d96d1..45ae085de9c215 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun May 29 23:17:29 2011  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* re.c (rb_reg_match): fix rdoc of Regexp#=~.
+	  patched by Tsuyoshi Sawada. [Bug #4781]
+
 Sun May 29 23:10:42 2011  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* lib/webrick/https.rb (WEBrick::HTTPRequest#parse_uri):
diff --git a/re.c b/re.c
index 67f38c630e5668..ec3fd70b4accec 100644
--- a/re.c
+++ b/re.c
@@ -2713,7 +2713,7 @@ reg_match_pos(VALUE re, VALUE *strp, long pos)
  *  The parser detects 'regexp-literal =~ expression' for the assignment.
  *  The regexp must be a literal without interpolation and placed at left hand side.
  *
- *  The assignment is not occur if the regexp is not a literal.
+ *  The assignment does not occur if the regexp is not a literal.
  *
  *     re = /(?<lhs>\w+)\s*=\s*(?<rhs>\w+)/
  *     re =~ "  x = y  "
@@ -2727,7 +2727,7 @@ reg_match_pos(VALUE re, VALUE *strp, long pos)
  *     /(?<lhs>\w+)\s*=\s*#{rhs_pat}/ =~ "x = y"
  *     p lhs    # undefined local variable
  *
- *  The assignment is not occur if the regexp is placed at right hand side.
+ *  The assignment does not occur if the regexp is placed at the right hand side.
  *
  *    "  x = y  " =~ /(?<lhs>\w+)\s*=\s*(?<rhs>\w+)/
  *    p lhs, rhs # undefined local variable