diff --git a/common/common.cpp b/common/common.cpp
index 407d0c465b..972b1ec0ad 100644
--- a/common/common.cpp
+++ b/common/common.cpp
@@ -707,28 +707,34 @@ long long TimestampDir( const wxString& aDirPath, const wxString& aFilespec )
 {
     long long timestamp = 0;
 
-#ifdef __WINDOWS__
-    // wxFileName construction is egregiously slow.  Construct it once and just swap out
-    // the filename thereafter.
-    WX_FILENAME fn( aDirPath, wxT( "dummyName" ) );
-    wxDir       dir( aDirPath );
-    wxString    fullname;
+#if defined(__WIN32__)
+    // Win32 version.
+    // Save time by not searching for each path twice: once in wxDir.GetNext() and once in
+    // wxFileName.GetModificationTime().  Also cuts out wxWidgets string-matching and case
+    // conversion by staying on the MSW side of things.
+    std::string filespec( aDirPath.t_str() );
+    filespec += '\\';
+    filespec += aFilespec.t_str();
 
-    if( dir.IsOpened() )
+    WIN32_FIND_DATA findData;
+    wxDateTime      lastModDate;
+
+    HANDLE fileHandle = ::FindFirstFile( filespec, &findData );
+
+    if( fileHandle != INVALID_HANDLE_VALUE )
     {
-        if( dir.GetFirst( &fullname, aFilespec ) )
+        do
         {
-            do
-            {
-                fn.SetFullName( fullname );
-                timestamp += fn.GetTimestamp();
-            }
-            while( dir.GetNext( &fullname ) );
+            ConvertFileTimeToWx( lastModDate, findData.ftLastWriteTime );
+            timestamp += lastModDate.GetValue().GetValue();
         }
+        while ( FindNextFile( fileHandle, &findData ) != 0);
     }
+
+    FindClose( fileHandle );
 #else
-    // POSIX version.  Save time by not converting between encodings -- do everything on
-    // the file-system side.
+    // POSIX version.
+    // Save time by not converting between encodings -- do everything on the file-system side.
     std::string filespec( aFilespec.fn_str() );
     std::string dir_path( aDirPath.fn_str() );