diff --git a/CHANGELOG.md b/CHANGELOG.md
index c847d59d7..62e928e84 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,7 @@
 
 BUG FIXES:
 
+  - core: Fix exception on installing VirtualBox [GH-6713]
   - guests/debian: Fix Docker install [GH-6722]
   - provisioners/chef: convert chef version to a string before comparing for
     the command builder [GH-6709, GH-6711]
diff --git a/plugins/hosts/darwin/cap/provider_install_virtualbox.rb b/plugins/hosts/darwin/cap/provider_install_virtualbox.rb
index 34f81ef3c..3eba42ac1 100644
--- a/plugins/hosts/darwin/cap/provider_install_virtualbox.rb
+++ b/plugins/hosts/darwin/cap/provider_install_virtualbox.rb
@@ -32,7 +32,7 @@ module VagrantPlugins
           dl.download!
 
           # Validate that the file checksum matches
-          actual = Vagrant::Util::FileChecksum.new(tf.path, Digest::SHA2).checksum
+          actual = FileChecksum.new(tf.path, Digest::SHA2).checksum
           if actual != SHA256SUM
             raise Vagrant::Errors::ProviderChecksumMismatch,
               provider: "virtualbox",
diff --git a/plugins/hosts/windows/cap/provider_install_virtualbox.rb b/plugins/hosts/windows/cap/provider_install_virtualbox.rb
index 2179d2164..4611990e4 100644
--- a/plugins/hosts/windows/cap/provider_install_virtualbox.rb
+++ b/plugins/hosts/windows/cap/provider_install_virtualbox.rb
@@ -33,7 +33,7 @@ module VagrantPlugins
           dl.download!
 
           # Validate that the file checksum matches
-          actual = Vagrant::Util::FileChecksum.new(tf.path, Digest::SHA2).checksum
+          actual = FileChecksum.new(tf.path, Digest::SHA2).checksum
           if actual != SHA256SUM
             raise Vagrant::Errors::ProviderChecksumMismatch,
               provider: "virtualbox",