diff --git a/include/audacity/Types.h b/include/audacity/Types.h
index f959269e5..9547b1915 100644
--- a/include/audacity/Types.h
+++ b/include/audacity/Types.h
@@ -48,22 +48,6 @@
 #include <vector>
 #include <wx/debug.h> // for wxASSERT
 #include <wx/string.h> // type used in inline function and member variable
-#include <wx/version.h> // for wxCHECK_VERSION
-
-#if !wxCHECK_VERSION(3, 1, 0)
-// For using std::unordered_map on wxString
-namespace std
-{
-   template<> struct hash< wxString > {
-      size_t operator () (const wxString &str) const // noexcept
-      {
-         auto stdstr = str.ToStdWstring(); // no allocations, a cheap fetch
-         using Hasher = hash< decltype(stdstr) >;
-         return Hasher{}( stdstr );
-      }
-   };
-}
-#endif
 
 // ----------------------------------------------------------------------------
 // TODO:  I'd imagine this header may be replaced by other public headers. But,