diff --git a/CHANGELOG.md b/CHANGELOG.md
index c896848ebcb..5951b55e2b3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,7 @@ BUG FIXES:
   - Finding V1 boxes now works properly again to avoid "box not found"
     errors. [GH-1691]
   - Setting hostname on SLES 11 works again. [GH-1781]
+  - `config.vm.guest` properly forces guests again. [GH-1800]
 
 ## 1.2.2 (April 23, 2013)
 
diff --git a/config/default.rb b/config/default.rb
index 97f92fc53c7..d4cb3aa8727 100644
--- a/config/default.rb
+++ b/config/default.rb
@@ -16,7 +16,6 @@
   config.vm.base_mac = nil
   config.vm.graceful_halt_retry_count = 60
   config.vm.graceful_halt_retry_interval = 1
-  config.vm.guest = :linux
 
   # Share SSH locally by default
   config.vm.network :forwarded_port,
diff --git a/lib/vagrant/guest.rb b/lib/vagrant/guest.rb
index ad4f06ecba5..1c0dab15820 100644
--- a/lib/vagrant/guest.rb
+++ b/lib/vagrant/guest.rb
@@ -69,7 +69,16 @@ def detect!
             guest_info = @guests[name]
             guest      = guest_info[0].new
 
-            if guest.detect?(@machine)
+            # If a specific guest was specified, then attempt to use that
+            # guest no matter what. Otherwise, only use it if it was detected.
+            use_this_guest = false
+            if @machine.config.vm.guest.nil?
+              use_this_guest = guest.detect?(@machine)
+            else
+              use_this_guest = @machine.config.vm.guest.to_sym == name.to_sym
+            end
+
+            if use_this_guest
               @logger.info("Detected: #{name}!")
               @chain << [name, guest]
               @name = name
diff --git a/plugins/kernel_v2/config/vm.rb b/plugins/kernel_v2/config/vm.rb
index 89f70b5c51f..e57042f6138 100644
--- a/plugins/kernel_v2/config/vm.rb
+++ b/plugins/kernel_v2/config/vm.rb
@@ -26,6 +26,7 @@ class VMConfig < Vagrant.plugin("2", :config)
       def initialize
         @graceful_halt_retry_count    = UNSET_VALUE
         @graceful_halt_retry_interval = UNSET_VALUE
+        @guest                        = UNSET_VALUE
         @hostname                     = UNSET_VALUE
         @provisioners                 = []
 
@@ -225,8 +226,12 @@ def define(name, options=nil, &block)
 
       def finalize!
         # Defaults
+        @guest = nil if @guest == UNSET_VALUE
         @hostname = nil if @hostname == UNSET_VALUE
 
+        # Set the guest properly
+        @guest = @guest.to_sym if @guest
+
         # If we haven't defined a single VM, then we need to define a
         # default VM which just inherits the rest of the configuration.
         define(DEFAULT_VM_NAME) if defined_vm_keys.empty?
diff --git a/test/unit/vagrant/guest_test.rb b/test/unit/vagrant/guest_test.rb
index d778ccd0517..b66ccc70872 100644
--- a/test/unit/vagrant/guest_test.rb
+++ b/test/unit/vagrant/guest_test.rb
@@ -10,6 +10,9 @@
   let(:machine) do
     double("machine").tap do |m|
       m.stub(:inspect => "machine")
+      m.stub(:config => double("config"))
+      m.config.stub(:vm => double("vm_config"))
+      m.config.vm.stub(:guest => nil)
     end
   end
 
@@ -143,6 +146,16 @@ def register_guest(name, parent, detect)
       subject.chain.map { |x| x[1] }.map(&:name).should == [:baz, :bar, :foo]
     end
 
+    it "detects the forced guest setting" do
+      register_guest(:foo, nil, false)
+      register_guest(:bar, nil, false)
+
+      machine.config.vm.stub(:guest => :bar)
+
+      subject.detect!
+      subject.name.should == :bar
+    end
+
     it "raises an exception if no guest can be detected" do
       expect { subject.detect! }.
         to raise_error(Vagrant::Errors::GuestNotDetected)