diff --git a/lib/gem/release/cmds/bump.rb b/lib/gem/release/cmds/bump.rb
index 22418ba..5971e96 100644
--- a/lib/gem/release/cmds/bump.rb
+++ b/lib/gem/release/cmds/bump.rb
@@ -76,7 +76,7 @@ class Bump < Base
           opts[:commit] = value
         end
 
-        opt '-m', '--message', descr(:message) do |value|
+        opt '-m', '--message MESSAGE', descr(:message) do |value|
           opts[:message] = value
         end