diff --git a/ChangeLog b/ChangeLog
index bf81a4faa9..99a1dbaee4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jan 26 16:43:34 2010  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* ext/strscan/strscan.c: fix rdoc. (length -> bytesize)
+	  reported by Kornelius Kalnbach. see [ruby-core:27792]
+
 Tue Jan 26 07:06:05 2010  Tanaka Akira  <akr@fsij.org>
 
 	* lib/matrix.rb: suppress warnings.
diff --git a/ext/strscan/strscan.c b/ext/strscan/strscan.c
index 490689b3d2..f7101823f5 100644
--- a/ext/strscan/strscan.c
+++ b/ext/strscan/strscan.c
@@ -353,9 +353,9 @@ strscan_concat(VALUE self, VALUE str)
 }
 
 /*
- * Returns the position of the scan pointer.  In the 'reset' position, this
+ * Returns the byte position of the scan pointer.  In the 'reset' position, this
  * value is zero.  In the 'terminated' position (i.e. the string is exhausted),
- * this value is the length of the string.
+ * this value is the bytesize of the string.
  *
  * In short, it's a 0-based index into the string.
  *
@@ -378,7 +378,7 @@ strscan_get_pos(VALUE self)
 /*
  * call-seq: pos=(n)
  *
- * Modify the scan pointer.
+ * Set the byte position of the scan pointer.
  *
  *   s = StringScanner.new('test string')
  *   s.pos = 7            # -> 7