diff --git a/lib/vagrant.rb b/lib/vagrant.rb
index eba026c51..3ae4c1154 100644
--- a/lib/vagrant.rb
+++ b/lib/vagrant.rb
@@ -227,6 +227,22 @@ module Vagrant
       requirements: requirements.join(", "),
       version: VERSION
   end
+
+  # This allows plugin developers to access the original environment before
+  # Vagrant even ran. This is useful when shelling out, especially to other
+  # Ruby processes.
+  #
+  # @return [Hash]
+  def self.original_env
+    {}.tap do |h|
+      ENV.each do |k,v|
+        if k.start_with?("VAGRANT_OLD_ENV")
+          key = k.sub(/^VAGRANT_OLD_ENV_/, "")
+          h[key] = v
+        end
+      end
+    end
+  end
 end
 
 # Default I18n to load the en locale
diff --git a/lib/vagrant/util/subprocess.rb b/lib/vagrant/util/subprocess.rb
index e249b72c1..e610151d2 100644
--- a/lib/vagrant/util/subprocess.rb
+++ b/lib/vagrant/util/subprocess.rb
@@ -91,6 +91,15 @@ module Vagrant
           end
         end
 
+        # Reset the Bundler environment back - this is required for anyone who
+        # is not using the official Vagrant installers and is running Vagrant
+        # via bundler
+        if defined?(Bundler::ORIGINAL_ENV)
+          Bundler::ORIGINAL_ENV.each do |k, v|
+            process.environment[k] = v
+          end
+        end
+
         # Set the environment on the process if we must
         if @options[:env]
           @options[:env].each do |k, v|
diff --git a/test/unit/vagrant_test.rb b/test/unit/vagrant_test.rb
index ec317a628..06f7489ca 100644
--- a/test/unit/vagrant_test.rb
+++ b/test/unit/vagrant_test.rb
@@ -98,4 +98,23 @@ describe Vagrant do
         to raise_error(Vagrant::Errors::VagrantVersionBad)
     end
   end
+
+  describe "original_env" do
+    before do
+      ENV["VAGRANT_OLD_ENV_foo"] = "test"
+      ENV["VAGRANT_OLD_ENV_bar"] = "test"
+    end
+
+    after do
+      ENV["VAGRANT_OLD_ENV_foo"] = "test"
+      ENV["VAGRANT_OLD_ENV_bar"] = "test"
+    end
+
+    it "should return the original environment" do
+      expect(Vagrant.original_env).to eq(
+        "foo" => "test",
+        "bar" => "test",
+      )
+    end
+  end
 end
diff --git a/website/docs/source/v2/other/environmental-variables.html.md b/website/docs/source/v2/other/environmental-variables.html.md
index c7099a6b7..b42e6774d 100644
--- a/website/docs/source/v2/other/environmental-variables.html.md
+++ b/website/docs/source/v2/other/environmental-variables.html.md
@@ -9,7 +9,15 @@ Vagrant has a set of environmental variables that can be used to
 configure and control it in a global way. This page lists those environmental
 variables.
 
-## VAGRANT\_CHECKPOINT\_DISABLE 
+## VAGRANT\_DEBUG\_LAUNCHER
+
+For performance reasons, especially for Windows users, Vagrant uses a static
+binary to launch the actual Vagrant process. If you have _very_ early issues
+when launching Vagrant from the official installer, you can specify the
+`VAGRANT_DEBUG_LAUNCHER` environment variable to output debugging information
+about the launch process.
+
+## VAGRANT\_CHECKPOINT\_DISABLE
 
 Vagrant does occasional network calls to check whether the version of Vagrant
 that is running locally is up to date. We understand that software making remote