diff --git a/Makefile.am b/Makefile.am
index a4de1bd3..72386d87 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -672,7 +672,6 @@ python_EXTRA_DIST=                                                           \
 
 ruby_EXTRA_DIST=                                                             \
   ruby/Gemfile                                                               \
-  ruby/Gemfile.lock                                                          \
   ruby/.gitignore                                                            \
   ruby/README.md                                                             \
   ruby/Rakefile                                                              \
diff --git a/ruby/Gemfile.lock b/ruby/Gemfile.lock
deleted file mode 100644
index d0eb9cc4..00000000
--- a/ruby/Gemfile.lock
+++ /dev/null
@@ -1,30 +0,0 @@
-PATH
-  remote: .
-  specs:
-    google-protobuf (3.0.0.alpha.5.0.5)
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    power_assert (0.2.2)
-    rake (10.4.2)
-    rake-compiler (0.9.5)
-      rake
-    rake-compiler-dock (0.5.1)
-    rubygems-tasks (0.2.4)
-    test-unit (3.0.9)
-      power_assert
-
-PLATFORMS
-  java
-  ruby
-
-DEPENDENCIES
-  google-protobuf!
-  rake-compiler
-  rake-compiler-dock
-  rubygems-tasks
-  test-unit
-
-BUNDLED WITH
-   1.11.2
diff --git a/ruby/google-protobuf.gemspec b/ruby/google-protobuf.gemspec
index 67b15c33..c1e02b07 100644
--- a/ruby/google-protobuf.gemspec
+++ b/ruby/google-protobuf.gemspec
@@ -10,16 +10,17 @@ Gem::Specification.new do |s|
   s.require_paths = ["lib"]
   s.files       = Dir.glob('lib/**/*.rb')
   if RUBY_PLATFORM == "java"
+    s.platform  = "java"
     s.files     += ["lib/google/protobuf_java.jar"]
   else
     s.files     += Dir.glob('ext/**/*')
     s.extensions= ["ext/google/protobuf_c/extconf.rb"]
-    s.add_development_dependency "rake-compiler-dock"
+    s.add_development_dependency "rake-compiler-dock", "~> 0.5.1"
   end
   s.test_files  = ["tests/basic.rb",
                   "tests/stress.rb",
                   "tests/generated_code_test.rb"]
-  s.add_development_dependency "rake-compiler"
-  s.add_development_dependency "test-unit"
-  s.add_development_dependency "rubygems-tasks"
+  s.add_development_dependency "rake-compiler", "~> 0.9.5"
+  s.add_development_dependency "test-unit", "~> 3.0.9"
+  s.add_development_dependency "rubygems-tasks", "~> 0.2.4"
 end