diff --git a/ChangeLog b/ChangeLog
index d472cfa111..cb6142dac5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Nov 15 11:25:20 2007  Tanaka Akira  <akr@fsij.org>
+
+	* ruby.c (usage): fix typo on --disable-gems option.
+	  pointed by Richard Kilmer.
+
 Wed Nov 14 16:16:17 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* test/net/http/test_https_proxy.rb
diff --git a/ruby.c b/ruby.c
index 51659e140a..b3d0a6c2f1 100644
--- a/ruby.c
+++ b/ruby.c
@@ -123,7 +123,7 @@ usage(const char *name)
 	"-w              turn warnings on for your script",
 	"-W[level]       set warning level; 0=silence, 1=medium, 2=verbose (default)",
 	"-x[directory]   strip off text before #!ruby line and perhaps cd to directory",
-	"--disable_gems  disable gem libraries",
+	"--disable-gems  disable gem libraries",
 	"--copyright     print the copyright",
 	"--version       print the version",
 	NULL