diff --git a/lib/vagrant/action/builtin/handle_box.rb b/lib/vagrant/action/builtin/handle_box.rb
index c9c5d130d..d8eb9c051 100644
--- a/lib/vagrant/action/builtin/handle_box.rb
+++ b/lib/vagrant/action/builtin/handle_box.rb
@@ -20,7 +20,7 @@ module Vagrant
         def call(env)
           machine = env[:machine]
 
-          if !machine.config.vm.box
+          if !machine.config.vm.box || machine.config.vm.box.to_s.empty?
             @logger.info("Skipping HandleBox because no box is set")
             return @app.call(env)
           end
diff --git a/lib/vagrant/vagrantfile.rb b/lib/vagrant/vagrantfile.rb
index 3dc7ada99..9d62c4224 100644
--- a/lib/vagrant/vagrantfile.rb
+++ b/lib/vagrant/vagrantfile.rb
@@ -197,7 +197,7 @@ module Vagrant
         local_keys = keys.dup
 
         # Load the box Vagrantfile, if there is one
-        if config.vm.box && boxes
+        if !config.vm.box.to_s.empty? && boxes
           box = boxes.find(config.vm.box, box_formats, config.vm.box_version)
           if box
             box_vagrantfile = find_vagrantfile(box.directory)
diff --git a/plugins/kernel_v2/config/vm.rb b/plugins/kernel_v2/config/vm.rb
index 1fa0d2e5e..acc6df6a6 100644
--- a/plugins/kernel_v2/config/vm.rb
+++ b/plugins/kernel_v2/config/vm.rb
@@ -734,6 +734,10 @@ module VagrantPlugins
           errors << I18n.t("vagrant.config.vm.clone_and_box")
         end
 
+        if box && box.empty?
+          errors << I18n.t("vagrant.config.vm.box_empty", machine_name: machine.name)
+        end
+
         errors << I18n.t("vagrant.config.vm.hostname_invalid_characters", name: machine.name) if \
           @hostname && @hostname !~ /^[a-z0-9][-.a-z0-9]*$/i
 
diff --git a/templates/locales/en.yml b/templates/locales/en.yml
index 6e08ab7e4..782904f49 100644
--- a/templates/locales/en.yml
+++ b/templates/locales/en.yml
@@ -1995,6 +1995,7 @@ en:
           Checksum type specified but "box_download_checksum" is blank
         box_download_checksum_notblank: |-
           Checksum specified but must also specify "box_download_checksum_type"
+        box_empty: "Box value for guest '%{machine_name}' is an empty string."
         box_missing: "A box must be specified."
         box_download_options_type: |-
           Found "box_download_options" specified as type '%{type}', should be a Hash
diff --git a/test/unit/plugins/guests/openwrt/guest_test.rb b/test/unit/plugins/guests/openwrt/guest_test.rb
new file mode 100644
index 000000000..e69de29bb
diff --git a/test/unit/plugins/kernel_v2/config/vm_test.rb b/test/unit/plugins/kernel_v2/config/vm_test.rb
index b8d06fae4..ebcef38a3 100644
--- a/test/unit/plugins/kernel_v2/config/vm_test.rb
+++ b/test/unit/plugins/kernel_v2/config/vm_test.rb
@@ -86,6 +86,12 @@ describe VagrantPlugins::Kernel_V2::VMConfig do
       assert_invalid
     end
 
+    it "cannot be an empty string" do
+      subject.box = ""
+      subject.finalize!
+      assert_invalid
+    end
+
     it "is not required if the provider says so" do
       machine.provider_options[:box_optional] = true
       subject.box = nil
diff --git a/test/unit/vagrant/action/builtin/handle_box_test.rb b/test/unit/vagrant/action/builtin/handle_box_test.rb
index 2d2eb271b..056ebc5bf 100644
--- a/test/unit/vagrant/action/builtin/handle_box_test.rb
+++ b/test/unit/vagrant/action/builtin/handle_box_test.rb
@@ -37,6 +37,15 @@ describe Vagrant::Action::Builtin::HandleBox do
     subject.call(env)
   end
 
+  it "works if box is empty string" do
+    machine.config.vm.box = ""
+    machine.config.vm.box_url = nil
+
+    expect(app).to receive(:call).with(env)
+
+    subject.call(env)
+  end
+
   it "doesn't do anything if a box exists" do
     allow(machine).to receive(:box).and_return(box)
 
diff --git a/test/unit/vagrant/vagrantfile_test.rb b/test/unit/vagrant/vagrantfile_test.rb
index d4b99445f..71f75d217 100644
--- a/test/unit/vagrant/vagrantfile_test.rb
+++ b/test/unit/vagrant/vagrantfile_test.rb
@@ -368,6 +368,17 @@ describe Vagrant::Vagrantfile do
         to raise_error(Vagrant::Errors::ProviderNotUsable)
     end
 
+    it "does not try to load the box if the box is empty" do
+      provider_cls = register_provider("foo")
+
+      configure do |config|
+        config.vm.box = ""
+      end
+
+      expect(boxes).not_to receive(:find)
+      results = subject.machine_config(:default, :foo, boxes)
+    end
+
     context "when provider validation is ignored" do
       before do
         configure do |config|