diff --git a/lib/jekyll.rb b/lib/jekyll.rb
index aebf4709..6cfbd70f 100644
--- a/lib/jekyll.rb
+++ b/lib/jekyll.rb
@@ -160,11 +160,13 @@ module Jekyll
 
       questionable_path.insert(0, "/") if questionable_path.start_with?("~")
       clean_path = File.expand_path(questionable_path, "/")
-      clean_path.sub!(%r!\A\w:/!, "/")
 
-      if clean_path.start_with?(base_directory.sub(%r!\A\w:/!, "/"))
+      return clean_path if clean_path.eql?(base_directory)
+
+      if clean_path.start_with?(base_directory.sub(%r!\z!, "/"))
         clean_path
       else
+        clean_path.sub!(%r!\A\w:/!, "/")
         File.join(base_directory, clean_path)
       end
     end
diff --git a/test/test_path_sanitization.rb b/test/test_path_sanitization.rb
index df7ef172..31a4b92e 100644
--- a/test/test_path_sanitization.rb
+++ b/test/test_path_sanitization.rb
@@ -28,4 +28,37 @@ class TestPathSanitization < JekyllUnitTest
     assert_equal source_dir("files", "hi.txt"),
                  Jekyll.sanitized_path(source_dir, "f./../../../../../../files/hi.txt")
   end
+
+  if Jekyll::Utils::Platforms.really_windows?
+    context "on Windows with absolute path" do
+      setup do
+        @base_path = "D:/demo"
+        @file_path = "D:/demo/_site"
+        allow(Dir).to receive(:pwd).and_return("D:/")
+      end
+
+      should "strip just the clean path drive name" do
+        assert_equal "D:/demo/_site",
+                     Jekyll.sanitized_path(@base_path, @file_path)
+      end
+    end
+
+    context "on Windows with file path has matching prefix" do
+      setup do
+        @base_path = "D:/site"
+        @file_path = "D:/sitemap.xml"
+        allow(Dir).to receive(:pwd).and_return("D:/")
+      end
+
+      should "not strip base path" do
+        assert_equal "D:/site/sitemap.xml",
+                     Jekyll.sanitized_path(@base_path, @file_path)
+      end
+    end
+  end
+
+  should "not strip base path if file path has matching prefix" do
+    assert_equal "/site/sitemap.xml",
+                 Jekyll.sanitized_path("/site", "sitemap.xml")
+  end
 end