diff --git a/plugins/synced_folders/rsync/command/rsync_auto.rb b/plugins/synced_folders/rsync/command/rsync_auto.rb
index b0cbfb6ae..42d9e4e55 100644
--- a/plugins/synced_folders/rsync/command/rsync_auto.rb
+++ b/plugins/synced_folders/rsync/command/rsync_auto.rb
@@ -72,6 +72,10 @@ module VagrantPlugins
                   throw :done, true if listenpath.start_with?(hostpath)
                 end
               end
+
+              # Make sure to return false if all else fails so that we
+              # don't sync to this machine.
+              false
             end
 
             # If it should be synced, store it for later
diff --git a/test/unit/plugins/synced_folders/rsync/command/rsync_auto_test.rb b/test/unit/plugins/synced_folders/rsync/command/rsync_auto_test.rb
new file mode 100644
index 000000000..7da7cc9a8
--- /dev/null
+++ b/test/unit/plugins/synced_folders/rsync/command/rsync_auto_test.rb
@@ -0,0 +1,99 @@
+require_relative "../../../../base"
+
+require Vagrant.source_root.join("plugins/synced_folders/rsync/command/rsync_auto")
+
+describe VagrantPlugins::SyncedFolderRSync::Command::RsyncAuto do
+  include_context "unit"
+
+  let(:argv) { [] }
+  let(:iso_env) do
+    # We have to create a Vagrantfile so there is a root path
+    env = isolated_environment
+    env.vagrantfile("")
+    env.create_vagrant_env
+  end
+
+  let(:synced_folders) { {} }
+
+  let(:helper_class) { VagrantPlugins::SyncedFolderRSync::RsyncHelper }
+
+  subject do
+    described_class.new(argv, iso_env).tap do |s|
+      s.stub(synced_folders: synced_folders)
+    end
+  end
+
+  describe "#callback" do
+    let(:paths) { {} }
+    let(:ssh_info) {{}}
+
+    def machine_stub(name)
+      double(name).tap do |m|
+        m.stub(ssh_info: ssh_info)
+      end
+    end
+
+    it "syncs modified folders to the proper path" do
+      paths["/foo"] = [
+        { machine: machine_stub("m1"), opts: double("opts_m1") },
+        { machine: machine_stub("m2"), opts: double("opts_m2") },
+      ]
+      paths["/bar"] = [
+        { machine: machine_stub("m3"), opts: double("opts_m3") },
+      ]
+
+      paths["/foo"].each do |data|
+        helper_class.should_receive(:rsync_single).
+          with(data[:machine], data[:machine].ssh_info, data[:opts]).
+          once
+      end
+
+      m = ["/foo/bar"]
+      a = []
+      r = []
+      subject.callback(paths, m, a, r)
+    end
+
+    it "syncs added folders to the proper path" do
+      paths["/foo"] = [
+        { machine: machine_stub("m1"), opts: double("opts_m1") },
+        { machine: machine_stub("m2"), opts: double("opts_m2") },
+      ]
+      paths["/bar"] = [
+        { machine: machine_stub("m3"), opts: double("opts_m3") },
+      ]
+
+      paths["/foo"].each do |data|
+        helper_class.should_receive(:rsync_single).
+          with(data[:machine], data[:machine].ssh_info, data[:opts]).
+          once
+      end
+
+      m = []
+      a = ["/foo/bar"]
+      r = []
+      subject.callback(paths, m, a, r)
+    end
+
+    it "syncs removed folders to the proper path" do
+      paths["/foo"] = [
+        { machine: machine_stub("m1"), opts: double("opts_m1") },
+        { machine: machine_stub("m2"), opts: double("opts_m2") },
+      ]
+      paths["/bar"] = [
+        { machine: machine_stub("m3"), opts: double("opts_m3") },
+      ]
+
+      paths["/foo"].each do |data|
+        helper_class.should_receive(:rsync_single).
+          with(data[:machine], data[:machine].ssh_info, data[:opts]).
+          once
+      end
+
+      m = []
+      a = []
+      r = ["/foo/bar"]
+      subject.callback(paths, m, a, r)
+    end
+  end
+end