diff --git a/lib/vagrant/environment.rb b/lib/vagrant/environment.rb
index db76f1884..dff913c39 100644
--- a/lib/vagrant/environment.rb
+++ b/lib/vagrant/environment.rb
@@ -349,7 +349,8 @@ module Vagrant
         box = nil
         if config.vm.box
           begin
-            box = boxes.find(config.vm.box, box_formats)
+            # TODO: support real version constraints
+            box = boxes.find(config.vm.box, box_formats, ">= 0")
           rescue Errors::BoxUpgradeRequired
             # Upgrade the box if we must
             @logger.info("Upgrading box during config load: #{config.vm.box}")
diff --git a/test/unit/support/isolated_environment.rb b/test/unit/support/isolated_environment.rb
index f69268ce7..0ea9bb9a8 100644
--- a/test/unit/support/isolated_environment.rb
+++ b/test/unit/support/isolated_environment.rb
@@ -109,6 +109,14 @@ module Unit
         }))
       end
 
+      # Create a Vagrantfile
+      if opts[:vagrantfile]
+        box_vagrantfile = box_dir.join("Vagrantfile")
+        box_vagrantfile.open("w") do |f|
+          f.write(opts[:vagrantfile])
+        end
+      end
+
       box_dir
     end
 
diff --git a/test/unit/vagrant/environment_test.rb b/test/unit/vagrant/environment_test.rb
index e7499aa7a..5dadef024 100644
--- a/test/unit/vagrant/environment_test.rb
+++ b/test/unit/vagrant/environment_test.rb
@@ -13,7 +13,7 @@ describe Vagrant::Environment do
 
   let(:env) do
     isolated_environment.tap do |e|
-      e.box2("base", :virtualbox)
+      e.box3("base", "1.0", :virtualbox)
       e.vagrantfile <<-VF
       Vagrant.configure("2") do |config|
         config.vm.box = "base"
@@ -469,7 +469,7 @@ Vagrant.configure("2") do |config|
 end
 VF
 
-        env.box2("base", :virtualbox)
+        env.box3("base", "1.0", :virtualbox)
       end
 
       env = environment.create_vagrant_env
@@ -486,7 +486,7 @@ Vagrant.configure("2") do |config|
 end
 VF
 
-        env.box2("base", :virtualbox)
+        env.box3("base", "1.0", :virtualbox)
       end
 
       env = environment.create_vagrant_env
@@ -588,7 +588,7 @@ Vagrant.configure("2") do |config|
 end
 VF
 
-        e.box2("base", :foo)
+        e.box3("base", "1.0", :foo)
       end
 
       # Verify that we can get the machine
@@ -621,7 +621,7 @@ Vagrant.configure("2") do |config|
 end
 VF
 
-        e.box2("base", :foo)
+        e.box3("base", "1.0", :foo)
       end
 
       # Verify that we can get the machine
@@ -648,8 +648,8 @@ Vagrant.configure("2") do |config|
 end
 VF
 
-        e.box2("base", :foo)
-        e.box2("base", :bar)
+        e.box3("base", "1.0", :foo)
+        e.box3("base", "1.0", :bar)
       end
 
       env = isolated_env.create_vagrant_env
@@ -694,7 +694,7 @@ Vagrant.configure("2") do |config|
 end
 VF
 
-        env.box2("base", :foo)
+        env.box3("base", "1.0", :foo)
       end
 
       env = environment.create_vagrant_env
@@ -713,7 +713,7 @@ Vagrant.configure("2") do |config|
 end
 VF
 
-        env.box2("base", :foo, :vagrantfile => <<-VF)
+        env.box3("base", "1.0", :foo, :vagrantfile => <<-VF)
 Vagrant.configure("2") do |config|
   config.ssh.port = 100
 end
@@ -735,7 +735,7 @@ Vagrant.configure("2") do |config|
 end
 VF
 
-        env.box2("base", :foo, :vagrantfile => <<-VF)
+        env.box3("base", "1.0", :foo, :vagrantfile => <<-VF)
 Vagrant.configure("2") do |config|
   config.ssh.port = 100
 end
@@ -760,7 +760,7 @@ Vagrant.configure("2") do |config|
 end
 VF
 
-        env.box2("base", :bar, :vagrantfile => <<-VF)
+        env.box3("base", "1.0", :bar, :vagrantfile => <<-VF)
 Vagrant.configure("2") do |config|
   config.ssh.port = 100
 end
@@ -782,13 +782,13 @@ Vagrant.configure("2") do |config|
 end
 VF
 
-        env.box2("base", :fA, :vagrantfile => <<-VF)
+        env.box3("base", "1.0", :fA, :vagrantfile => <<-VF)
 Vagrant.configure("2") do |config|
   config.ssh.port = 100
 end
 VF
 
-        env.box2("base", :fB, :vagrantfile => <<-VF)
+        env.box3("base", "1.0", :fB, :vagrantfile => <<-VF)
 Vagrant.configure("2") do |config|
   config.ssh.port = 200
 end
@@ -835,7 +835,7 @@ Vagrant.configure("2") do |config|
 end
 VF
 
-        e.box2("base", :foo)
+        e.box3("base", "1.0", :foo)
       end
 
       env = isolated_env.create_vagrant_env