Rails is an implicit dependency. It doesn't need to be in the gemspec

README

@@ -7,6 +7,8 @@ Records how long your rails app spends in Mongo, and outputs it to the log, i.e.
 
 To use, just add the gem to your Gemfile and restart your app:
 
-    gem 'mongo-rails-instrumentation', '~>0.1'
+    gem 'mongo-rails-instrumentation', '~>0.2'
 
-This gem's home is on github at https://github.com/tomafro/mongo-rails-instrumentation, so please add comments, suggestions and improvements there.
+It's been tested with rails 3.0, and should work with rails 3.1 too.
+
+This gem's home is on github at https://github.com/tomafro/mongo-rails-instrumentation, so please add comments, suggestions and improvements there.

lib/mongo/rails/instrumentation/version.rb

@@ -1,7 +1,7 @@
 module Mongo
   module Rails
     module Instrumentation
-      VERSION = "0.1.0"
+      VERSION = "0.2.1"
     end
   end
 end

mongo-rails-instrumentation.gemspec

@@ -16,6 +16,4 @@ Gem::Specification.new do |s|
   s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")
   s.executables   = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
   s.require_paths = ["lib"]
-
-  s.add_dependency 'rails', '~>3.0.0'
 end