diff --git a/ChangeLog b/ChangeLog
index a1b4bf4edd..f4fae9ea54 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Jun 11 15:27:17 2009  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* lib/prime.rb: documentation typo fixed.  a patch from okkez.
+	  [ruby-dev:38586]
+
 Wed Jun 10 18:15:17 2009  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* dir.c (dir_s_getwd): directory path's encoding should be filesystem's
diff --git a/lib/prime.rb b/lib/prime.rb
index ce71d5e00f..4114beb292 100644
--- a/lib/prime.rb
+++ b/lib/prime.rb
@@ -118,7 +118,7 @@ class Prime
   # if no block given. 
   #
   # == Description
-  # Calls +block+ once for each prime numer, passing the prime as
+  # Calls +block+ once for each prime number, passing the prime as
   # a parameter.
   #
   # +ubound+::
@@ -127,7 +127,7 @@ class Prime
   #
   # == Note
   # +Prime+.+new+ returns a object extended by +Prime+::+OldCompatibility+
-  # in order to compatibility to Ruby 1.9, and +Prime+#each is overwritten
+  # in order to compatibility to Ruby 1.8, and +Prime+#each is overwritten
   # by +Prime+::+OldCompatibility+#+each+.
   #
   # +Prime+.+new+ is now obsolete. Use +Prime+.+instance+.+each+ or simply
diff --git a/version.h b/version.h
index 249ec13506..a698666308 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "1.9.1"
 #define RUBY_RELEASE_DATE "2009-05-22"
-#define RUBY_PATCHLEVEL 172
+#define RUBY_PATCHLEVEL 173
 #define RUBY_VERSION_MAJOR 1
 #define RUBY_VERSION_MINOR 9
 #define RUBY_VERSION_TEENY 1