diff --git a/CHANGELOG.md b/CHANGELOG.md
index a7f921b39..4856fa5b2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
   - `config.ssh.port` can be specified and takes highest precedence if specified.
     Otherwise, Vagrant will still attempt to auto-detect the port. [GH-363]
+  - Get rid of RubyGems deprecations introduced with RubyGems 1.8.x
 
 ## 0.7.4 (May 12, 2011)
 
diff --git a/lib/vagrant/plugin.rb b/lib/vagrant/plugin.rb
index 5df4e89d0..b6f92fc41 100644
--- a/lib/vagrant/plugin.rb
+++ b/lib/vagrant/plugin.rb
@@ -21,18 +21,31 @@ module Vagrant
     # load path. This file is loaded to kick off the load sequence
     # for that plugin.
     def self.load!
+      # RubyGems 1.8.0 deprecated `source_index`. Gem::Specification is the
+      # new replacement. For now, we support both, but special-case 1.8.x
+      # so that we avoid deprecation messages.
+      index = Gem::VERSION >= "1.8.0" ? Gem::Specification : Gem.source_index
+
       # Stupid hack since Rails 2.3.x overrides Gem.source_index with their
       # own incomplete replacement which causes issues.
-      index = Gem.source_index
       index = [index.installed_source_index, index.vendor_source_index] if defined?(Rails::VendorGemSourceIndex) && index.is_a?(Rails::VendorGemSourceIndex)
 
       # Look for a vagrant_init.rb in all the gems, but only the
       # latest version of the gems.
       [index].flatten.each do |source|
-        source.latest_specs.each do |spec|
-          file = Gem.searcher.matching_files(spec, "vagrant_init.rb").first
-          next if !file
+        # In 1.6.0, added the option of including prerelease gems, which is
+        # useful for developers.
+        specs = Gem::VERSION >= "1.6.0" ? source.latest_specs(true) : source.latest_specs
 
+        source.latest_specs.each do |spec|
+          file = nil
+          if Gem::VERSION >= "1.8.0"
+            file = spec.matches_for_glob("**/vagrant_init.rb").first
+          else
+            file = Gem.searcher.matching_files(spec, "vagrant_init.rb").first
+          end
+
+          next if !file
           @@plugins << new(spec, file)
         end
       end