diff --git a/plugins/providers/hyperv/sync_helper.rb b/plugins/providers/hyperv/sync_helper.rb
index 601ef44a4..003a625c7 100644
--- a/plugins/providers/hyperv/sync_helper.rb
+++ b/plugins/providers/hyperv/sync_helper.rb
@@ -265,7 +265,8 @@ module VagrantPlugins
             source_copy = platform_join windows_temp, filename, is_windows: !Vagrant::Util::Platform.wsl?
             FileUtils.mv source, source_copy
             source = source_copy
-            hyperv_copy machine, source, dest_dir
+            win_source_path = Vagrant::Util::Platform.windows_path(source, :disable_unc)
+            hyperv_copy machine, win_source_path, dest_dir
           else
             machine.communicate.upload(source, dest)
           end
diff --git a/test/unit/plugins/providers/hyperv/sync_helper_test.rb b/test/unit/plugins/providers/hyperv/sync_helper_test.rb
index 02b4e46dd..bc3b83fb1 100644
--- a/test/unit/plugins/providers/hyperv/sync_helper_test.rb
+++ b/test/unit/plugins/providers/hyperv/sync_helper_test.rb
@@ -701,6 +701,7 @@ describe VagrantPlugins::HyperV::SyncHelper do
             let(:is_windows) { host_type == :Windows }
             let(:source) { sources[host_type] }
             let(:new_source) { new_sources[host_type] }
+            let(:new_source_windows) { new_sources[:Windows] }
 
             context "uploads file by Hyper-V daemons when applicable" do
               let(:windows_temp) { windows_temps[host_type] }
@@ -709,6 +710,8 @@ describe VagrantPlugins::HyperV::SyncHelper do
                 allow(subject).to receive(:hyperv_copy?).with(machine).and_return(true)
                 allow(subject).to receive(:format_windows_temp).and_return(windows_temp)
                 allow(Vagrant::Util::Platform).to receive(:wsl?).and_return(!is_windows)
+                allow(Vagrant::Util::Platform).to receive(:windows_path).
+                  with(new_source, :disable_unc).and_return(new_source_windows)
                 allow(FileUtils).to receive(:rm_f)
                 allow(FileUtils).to receive(:mv)
                 allow(subject).to receive(:hyperv_copy)
@@ -724,7 +727,7 @@ describe VagrantPlugins::HyperV::SyncHelper do
               end
 
               it "calls Hyper-V cmdlet to copy file" do
-                expect(subject).to receive(:hyperv_copy).with(machine, new_source, dest_dir)
+                expect(subject).to receive(:hyperv_copy).with(machine, new_source_windows, dest_dir)
               end
             end