diff --git a/lib/vagrant/util/platform.rb b/lib/vagrant/util/platform.rb
index 789d61ece..e1f2ea29c 100644
--- a/lib/vagrant/util/platform.rb
+++ b/lib/vagrant/util/platform.rb
@@ -392,8 +392,9 @@ module Vagrant
         # @param [String, Pathname] path Path to convert
         # @return [String]
         def wsl_to_windows_path(path)
+          path = path.to_s
           if wsl? && wsl_windows_access? && !path.match(/^[a-zA-Z]:/)
-            path = File.expand_path(path.to_s)
+            path = File.expand_path(path)
             if wsl_path?(path)
               parts = path.split("/")
               parts.delete_if(&:empty?)
@@ -405,13 +406,13 @@ module Vagrant
               end
               path = [root_path, *parts].join("\\")
             else
-              path = path.to_s.sub("/mnt/", "")
+              path = path.sub("/mnt/", "")
               parts = path.split("/")
               parts.first << ":"
               path = parts.join("\\")
             end
           end
-          path.to_s
+          path
         end
 
         # Takes a windows path and formats it to the
diff --git a/test/unit/vagrant/util/platform_test.rb b/test/unit/vagrant/util/platform_test.rb
index f43afd1d8..396148839 100644
--- a/test/unit/vagrant/util/platform_test.rb
+++ b/test/unit/vagrant/util/platform_test.rb
@@ -353,6 +353,10 @@ describe Vagrant::Util::Platform do
             it "should include rootfs when accessing non-home path" do
               expect(subject.wsl_to_windows_path("/tmp/test")).to include("rootfs")
             end
+
+            it "should properly handle Pathname" do
+              expect(subject.wsl_to_windows_path(Pathname.new("/tmp/test"))).to include("rootfs")
+            end
           end
         end
       end