diff --git a/lib/vagrant/environment.rb b/lib/vagrant/environment.rb
index de3b88066..f0b8114ff 100644
--- a/lib/vagrant/environment.rb
+++ b/lib/vagrant/environment.rb
@@ -175,9 +175,7 @@ module Vagrant
       # Load any global plugins
       Vagrant::Plugin::Manager.instance.load_plugins(plugins)
 
-      if !vagrantfile.config.vagrant.plugins.empty?
-        plugins = process_configured_plugins
-      end
+      plugins = process_configured_plugins
 
       # Call the hooks that does not require configurations to be loaded
       # by using a "clean" action runner
@@ -922,6 +920,49 @@ module Vagrant
 
     protected
 
+    # Attempt to guess the configured provider in use. Will fallback
+    # to the default provider if an explicit provider name is not
+    # provided. This can be pretty error prone, but is used during
+    # initial environment setup to allow loading plugins so it doesn't
+    # need to be perfect
+    #
+    # @return [String]
+    def guess_provider
+      gp = nil
+      ARGV.each_with_index do |val, idx|
+        if val.start_with?("--provider=")
+          gp = val.split("=", 2).last
+          break
+        elsif val == "--provider"
+          gp = ARGV[idx+1]
+          break
+        end
+      end
+      return gp if gp
+      begin
+        default_provider
+      rescue Errors::NoDefaultProvider
+        # if a provider cannot be determined just return nil
+        nil
+      end
+    end
+
+    # Load any configuration provided by guests defined within
+    # the Vagrantfile to pull plugin information they may have
+    # defined.
+    def find_configured_plugins
+      plugins = []
+      provider = guess_provider
+      vagrantfile.machine_names.each do |mname|
+        ldp = @local_data_path.join("machines/#{mname}/#{provider}") if @local_data_path
+        plugins << vagrantfile.machine_config(mname, guess_provider, boxes, ldp)[:config]
+      end
+      result = plugins.reverse.inject(Vagrant::Util::HashWithIndifferentAccess.new) do |memo, val|
+        Vagrant::Util::DeepMerge.deep_merge(memo, val.vagrant.plugins)
+      end
+      Vagrant::Util::DeepMerge.deep_merge(result, vagrantfile.config.vagrant.plugins)
+    end
+
     # Check for any local plugins defined within the Vagrantfile. If
     # found, validate they are available. If they are not available,
     # request to install them, or raise an exception
@@ -939,7 +980,7 @@ module Vagrant
       # Check if defined plugins are installed
       installed = Plugin::Manager.instance.installed_plugins
       needs_install = []
-      config_plugins = vagrantfile.config.vagrant.plugins
+      config_plugins = find_configured_plugins
       config_plugins.each do |name, info|
         if !installed[name]
           needs_install << name
diff --git a/test/unit/vagrant/environment_test.rb b/test/unit/vagrant/environment_test.rb
index 6c92cd5ba..8be6ddeed 100644
--- a/test/unit/vagrant/environment_test.rb
+++ b/test/unit/vagrant/environment_test.rb
@@ -165,7 +165,7 @@ describe Vagrant::Environment do
 
         collection = double("collection")
         expect(Vagrant::BoxCollection).to receive(:new).with(
-          env.homedir.join("boxes"), anything).and_return(collection)
+          env.homedir.join("boxes"), anything).twice.and_return(collection)
         expect(collection).to receive(:upgrade_v1_1_v1_5).once
         subject
       end
@@ -761,6 +761,7 @@ VF
     before do
       m = Vagrant.plugin("2").manager
       allow(m).to receive(:providers).and_return(plugin_providers)
+      allow_any_instance_of(described_class).to receive(:process_configured_plugins)
     end
 
     it "is the highest matching usable provider" do
@@ -1431,6 +1432,108 @@ VF
     end
   end
 
+  describe "guess_provider" do
+    before { allow_any_instance_of(described_class).to receive(:process_configured_plugins) }
+
+    it "should return the default provider by default" do
+      expect(subject).to receive(:default_provider).and_return("default_provider")
+      expect(subject.send(:guess_provider)).to eq("default_provider")
+    end
+
+    context "when provider is defined via command line argument" do
+      before { stub_const("ARGV", argv) }
+
+      context "when provider is given as single argument" do
+        let(:argv) { ["--provider=single_arg"] }
+
+        it "should return the provider name" do
+          expect(subject.send(:guess_provider)).to eq("single_arg")
+        end
+      end
+
+      context "when provider is given as two arguments" do
+        let(:argv) { ["--provider", "double_arg"] }
+
+        it "should return the provider name" do
+          expect(subject.send(:guess_provider)).to eq("double_arg")
+        end
+      end
+    end
+
+    context "when no default provider is available" do
+      before {
+        expect(subject).to receive(:default_provider).
+          and_raise(Vagrant::Errors::NoDefaultProvider) }
+
+      it "should return a nil value" do
+        expect(subject.send(:guess_provider)).to be_nil
+      end
+    end
+  end
+
+  describe "#find_configured_plugins" do
+    before do
+      allow_any_instance_of(described_class).to receive(:guess_provider).and_return(:dummy)
+      allow_any_instance_of(described_class).to receive(:process_configured_plugins)
+    end
+
+    it "should find no plugins when no plugins are configured" do
+      expect(subject.send(:find_configured_plugins)).to be_empty
+    end
+
+    context "when plugins are defined in the Vagrantfile" do
+      before do
+        env.vagrantfile <<-VF
+          Vagrant.configure("2") do |config|
+            config.vagrant.plugins = "vagrant-plugin"
+          end
+          VF
+      end
+
+      it "should return the vagrant-plugin" do
+        expect(subject.send(:find_configured_plugins).keys).to include("vagrant-plugin")
+      end
+    end
+
+    context "when plugins are defined in the Vagrantfile of a box" do
+      before do
+        env.box3("foo", "1.0", :dummy, vagrantfile: <<-VF)
+          Vagrant.configure("2") do |config|
+            config.vagrant.plugins = "vagrant-plugin"
+          end
+        VF
+        env.vagrantfile <<-VF
+          Vagrant.configure("2") do |config|
+            config.vm.box = "foo"
+          end
+        VF
+      end
+
+      it "should return the vagrant-plugin" do
+        expect(subject.send(:find_configured_plugins).keys).to include("vagrant-plugin")
+      end
+    end
+
+    context "when the box does not match the provider" do
+      before do
+        env.box3("foo", "1.0", :other, vagrantfile: <<-VF)
+          Vagrant.configure("2") do |config|
+            config.vagrant.plugins = "vagrant-plugin"
+          end
+        VF
+        env.vagrantfile <<-VF
+          Vagrant.configure("2") do |config|
+            config.vm.box = "foo"
+          end
+        VF
+      end
+
+      it "should not return the vagrant-plugin" do
+        expect(subject.send(:find_configured_plugins).keys).not_to include("vagrant-plugin")
+      end
+    end
+  end
+
   describe "#process_configured_plugins" do
     let(:env) do
       isolated_environment.tap do |e|
diff --git a/test/unit/vagrant/util/ssh_test.rb b/test/unit/vagrant/util/ssh_test.rb
index 9d84f0225..88d51539e 100644
--- a/test/unit/vagrant/util/ssh_test.rb
+++ b/test/unit/vagrant/util/ssh_test.rb
@@ -39,7 +39,7 @@ describe Vagrant::Util::SSH do
       dsa_authentication: true
     }}
 
-    let(:ssh_path) { "/usr/bin/ssh" }
+    let(:ssh_path) { /.*ssh/ }
 
     it "searches original PATH for executable" do
       expect(Vagrant::Util::Which).to receive(:which).with("ssh", original_path: true).and_return("valid-return")
@@ -97,8 +97,6 @@ describe Vagrant::Util::SSH do
         dsa_authentication: true
       }}
 
-      let(:ssh_path) { "/usr/bin/ssh" }
-
       it "uses the IdentityFile argument and escapes the '%' character" do
         allow(Vagrant::Util::SafeExec).to receive(:exec).and_return(nil)
         described_class.exec(ssh_info)
@@ -247,7 +245,7 @@ describe Vagrant::Util::SSH do
       it "enables ssh config loading" do
         allow(Vagrant::Util::SafeExec).to receive(:exec).and_return(nil)
         expect(Vagrant::Util::SafeExec).to receive(:exec) do |exe_path, *args|
-          expect(exe_path).to eq(ssh_path)
+          expect(exe_path).to match(ssh_path)
           config_options = ["-F", "/path/to/config"]
           expect(args & config_options).to eq(config_options)
         end