diff --git a/include/wx/msw/private/webrequest_winhttp.h b/include/wx/msw/private/webrequest_winhttp.h
index 7dd322eb3f..58bfcc52bd 100644
--- a/include/wx/msw/private/webrequest_winhttp.h
+++ b/include/wx/msw/private/webrequest_winhttp.h
@@ -10,6 +10,8 @@
 #ifndef _WX_MSW_WEBREQUEST_WINHTTP_H
 #define _WX_MSW_WEBREQUEST_WINHTTP_H
 
+#include "wx/private/webrequest.h"
+
 #include "wx/msw/wrapwin.h"
 #include <winhttp.h>
 #include "wx/buffer.h"
diff --git a/include/wx/osx/private/webrequest_urlsession.h b/include/wx/osx/private/webrequest_urlsession.h
index 06745fb9a4..4d6f3721fa 100644
--- a/include/wx/osx/private/webrequest_urlsession.h
+++ b/include/wx/osx/private/webrequest_urlsession.h
@@ -12,6 +12,8 @@
 
 #if wxUSE_WEBREQUEST_URLSESSION
 
+#include "wx/private/webrequest.h"
+
 DECLARE_WXCOCOA_OBJC_CLASS(NSURLSession);
 DECLARE_WXCOCOA_OBJC_CLASS(NSURLSessionTask);
 DECLARE_WXCOCOA_OBJC_CLASS(wxWebSessionDelegate);
diff --git a/include/wx/private/webrequest.h b/include/wx/private/webrequest.h
new file mode 100644
index 0000000000..c4746f7fe9
--- /dev/null
+++ b/include/wx/private/webrequest.h
@@ -0,0 +1,25 @@
+///////////////////////////////////////////////////////////////////////////////
+// Name:        wx/private/webrequest.h
+// Purpose:     wxWebRequest implementation classes
+// Author:      Vadim Zeitlin
+// Created:     2020-12-26
+// Copyright:   (c) 2020 Vadim Zeitlin <vadim@wxwidgets.org>
+// Licence:     wxWindows licence
+///////////////////////////////////////////////////////////////////////////////
+
+#ifndef _WX_PRIVATE_WEBREQUEST_H_
+#define _WX_PRIVATE_WEBREQUEST_H_
+
+// ----------------------------------------------------------------------------
+// wxWebSessionFactory
+// ----------------------------------------------------------------------------
+
+class wxWebSessionFactory
+{
+public:
+    virtual wxWebSession* Create() = 0;
+
+    virtual ~wxWebSessionFactory() { }
+};
+
+#endif // _WX_PRIVATE_WEBREQUEST_H_
diff --git a/include/wx/private/webrequest_curl.h b/include/wx/private/webrequest_curl.h
index f3659866db..c88e1d16db 100644
--- a/include/wx/private/webrequest_curl.h
+++ b/include/wx/private/webrequest_curl.h
@@ -12,6 +12,8 @@
 
 #if wxUSE_WEBREQUEST_CURL
 
+#include "wx/private/webrequest.h"
+
 #include "wx/thread.h"
 #include "wx/vector.h"
 
diff --git a/include/wx/webrequest.h b/include/wx/webrequest.h
index 7cc8417bdc..8195d99a91 100644
--- a/include/wx/webrequest.h
+++ b/include/wx/webrequest.h
@@ -26,6 +26,7 @@
 
 class wxWebResponse;
 class wxWebSession;
+class wxWebSessionFactory;
 class wxWebAuthChallenge;
 
 WX_DECLARE_STRING_HASH_MAP(wxString, wxWebRequestHeaderMap);
@@ -195,14 +196,6 @@ private:
     wxDECLARE_NO_COPY_CLASS(wxWebAuthChallenge);
 };
 
-class WXDLLIMPEXP_NET wxWebSessionFactory
-{
-public:
-    virtual wxWebSession* Create() = 0;
-
-    virtual ~wxWebSessionFactory() { }
-};
-
 extern WXDLLIMPEXP_DATA_NET(const char) wxWebSessionBackendDefault[];
 extern WXDLLIMPEXP_DATA_NET(const char) wxWebSessionBackendWinHTTP[];
 extern WXDLLIMPEXP_DATA_NET(const char) wxWebSessionBackendURLSession[];
@@ -228,9 +221,6 @@ public:
 
     static wxWebSession* New(const wxString& backend = wxWebSessionBackendDefault);
 
-    static void RegisterFactory(const wxString& backend,
-                                const wxSharedPtr<wxWebSessionFactory>& factory);
-
     static bool IsBackendAvailable(const wxString& backend);
 
 protected:
@@ -239,6 +229,9 @@ protected:
     const wxWebRequestHeaderMap& GetHeaders() const { return m_headers; }
 
 private:
+    static void RegisterFactory(const wxString& backend,
+                                const wxSharedPtr<wxWebSessionFactory>& factory);
+
     // Make it a friend to allow accessing our m_headers.
     friend class wxWebRequest;
 
diff --git a/interface/wx/webrequest.h b/interface/wx/webrequest.h
index 8172458560..76ea78de21 100644
--- a/interface/wx/webrequest.h
+++ b/interface/wx/webrequest.h
@@ -507,17 +507,6 @@ public:
     */
     static wxWebSession* New(const wxString& backend = wxWebSessionBackendDefault);
 
-    /**
-        Allows the registering of new backend for wxWebSession.
-
-        backend can be used as an argument to New().
-
-        @param backend The name for the new backend to be registered under
-        @param factory A shared pointer to the factory which creates the appropriate backend.
-    */
-    static void RegisterFactory(const wxString& backend,
-                                const wxSharedPtr<wxWebSessionFactory>& factory);
-
     /**
         Allows to check if the specified backend is available at runtime.
 
@@ -527,29 +516,6 @@ public:
     static bool IsBackendAvailable(const wxString& backend);
 };
 
-/**
-    @class wxWebSessionFactory
-
-    An abstract factory class for creation wxWebSession backends.
-
-    Each implementation of wxWebSession should have its own factory.
-
-    @since 3.1.5
-
-    @library{wxnet}
-    @category{net}
-
-    @see wxWebSession
-*/
-class wxWebSessionFactory
-{
-public:
-    /**
-        Creates a new web session object.
-    */
-    virtual wxWebSession* Create();
-};
-
 /**
     @class wxWebRequestEvent
 
diff --git a/src/common/webrequest.cpp b/src/common/webrequest.cpp
index ecd4e4d7b5..3f6b02cdb1 100644
--- a/src/common/webrequest.cpp
+++ b/src/common/webrequest.cpp
@@ -27,6 +27,8 @@
     #include "wx/utils.h"
 #endif
 
+#include "wx/private/webrequest.h"
+
 #if wxUSE_WEBREQUEST_WINHTTP
 #include "wx/msw/private/webrequest_winhttp.h"
 #endif