diff --git a/test/unit/plugins/synced_folders/rsync/helper_test.rb b/test/unit/plugins/synced_folders/rsync/helper_test.rb
index 28e2b58eb..0230bf343 100644
--- a/test/unit/plugins/synced_folders/rsync/helper_test.rb
+++ b/test/unit/plugins/synced_folders/rsync/helper_test.rb
@@ -60,7 +60,7 @@ describe VagrantPlugins::SyncedFolderRSync::RsyncHelper do
       Vagrant::Util::Platform.should_receive(:cygwin_windows_path).and_return("foo")
 
       Vagrant::Util::Subprocess.should_receive(:execute).with do |*args|
-        expect(args[args.length - 3]).to eql("foo")
+        expect(args[args.length - 3]).to eql("foo/")
       end
 
       subject.rsync_single(machine, ssh_info, opts)
@@ -80,7 +80,8 @@ describe VagrantPlugins::SyncedFolderRSync::RsyncHelper do
         opts[:guestpath] = "/bar"
 
         Vagrant::Util::Subprocess.should_receive(:execute).with do |*args|
-          expect(args[args.length - 3]).to eql(Vagrant::Util::Platform.fs_real_path("/foo").to_s)
+          expected = Vagrant::Util::Platform.fs_real_path("/foo").to_s
+          expect(args[args.length - 3]).to eql("#{expected}/")
           expect(args[args.length - 2]).to include("/bar")
         end
 
@@ -94,7 +95,7 @@ describe VagrantPlugins::SyncedFolderRSync::RsyncHelper do
         hostpath_expanded = File.expand_path(opts[:hostpath], machine.env.root_path)
 
         Vagrant::Util::Subprocess.should_receive(:execute).with do |*args|
-          expect(args[args.length - 3]).to eql(hostpath_expanded)
+          expect(args[args.length - 3]).to eql("#{hostpath_expanded}/")
           expect(args[args.length - 2]).to include("/bar")
         end
 
diff --git a/test/unit/support/shared/virtualbox_context.rb b/test/unit/support/shared/virtualbox_context.rb
index 6a13f58bc..13f3d16bc 100644
--- a/test/unit/support/shared/virtualbox_context.rb
+++ b/test/unit/support/shared/virtualbox_context.rb
@@ -1,4 +1,6 @@
 shared_context "virtualbox" do
+  include_context "unit"
+
   let(:vbox_context) { true                                }
   let(:uuid)         { "1234-abcd-5678-efgh"               }
   let(:vbox_version) { "4.3.4"                             }
@@ -27,4 +29,11 @@ shared_context "virtualbox" do
       with("VBoxManage", "showvminfo", kind_of(String), kind_of(Hash)).
       and_return(subprocess_result(exit_code: 0))
   end
+
+  around do |example|
+    # On Windows, we don't want to accidentally call the actual VirtualBox
+    with_temp_env("VBOX_INSTALL_PATH" => nil) do
+      example.run
+    end
+  end
 end