diff --git a/plugins/kernel_v2/config/vm.rb b/plugins/kernel_v2/config/vm.rb
index 563ed1719..4b35495aa 100644
--- a/plugins/kernel_v2/config/vm.rb
+++ b/plugins/kernel_v2/config/vm.rb
@@ -307,7 +307,7 @@ module VagrantPlugins
         # Defaults
         @base_mac = nil if @base_mac == UNSET_VALUE
         @boot_timeout = 300 if @boot_timeout == UNSET_VALUE
-        @box_check_update = nil if @box_check_update == UNSET_VALUE
+        @box_check_update = true if @box_check_update == UNSET_VALUE
         @box_download_ca_cert = nil if @box_download_ca_cert == UNSET_VALUE
         @box_download_checksum = nil if @box_download_checksum == UNSET_VALUE
         @box_download_checksum_type = nil if @box_download_checksum_type == UNSET_VALUE
diff --git a/test/unit/plugins/kernel_v2/config/vm_test.rb b/test/unit/plugins/kernel_v2/config/vm_test.rb
index 73f0a85fd..77afcff5d 100644
--- a/test/unit/plugins/kernel_v2/config/vm_test.rb
+++ b/test/unit/plugins/kernel_v2/config/vm_test.rb
@@ -33,10 +33,10 @@ describe VagrantPlugins::Kernel_V2::VMConfig do
   end
 
   context "#box_check_update" do
-    it "defaults to nil" do
+    it "defaults to true" do
       subject.finalize!
 
-      expect(subject.box_check_update).to be_nil
+      expect(subject.box_check_update).to be_true
     end
   end