diff --git a/include/wx/filedlg.h b/include/wx/filedlg.h
index b068129ae2..14f667fa68 100644
--- a/include/wx/filedlg.h
+++ b/include/wx/filedlg.h
@@ -114,6 +114,9 @@ public:
     virtual wxString GetCurrentlySelectedFilename() const
         { return m_currentlySelectedFilename; }
 
+    virtual int GetCurrentlySelectedFilterIndex () const
+        { return m_currentlySelectedFilterIndex; }
+
     // this function is called with wxFileDialog as parameter and should
     // create the window containing the extra controls we want to show in it
     typedef wxWindow *(*ExtraControlCreatorFunction)(wxWindow*);
@@ -153,6 +156,12 @@ protected:
     // GetCurrentlySelectedFilename().
     wxString      m_currentlySelectedFilename;
 
+    // Currently selected, but not yet necessarily accepted by the user, file
+    // type (a.k.a. filter) index. This should be updated whenever the
+    // selection in the control changes by the platform-specific code to
+    // provide a useful implementation of GetCurrentlySelectedFilterIndex().
+    int           m_currentlySelectedFilterIndex;
+
     wxWindow*     m_extraControl;
 
     // returns true if control is created (if it already exists returns false)
diff --git a/include/wx/msw/filedlg.h b/include/wx/msw/filedlg.h
index 0b3b780d2a..a83192b6e9 100644
--- a/include/wx/msw/filedlg.h
+++ b/include/wx/msw/filedlg.h
@@ -44,6 +44,9 @@ public:
     // called from the hook procedure on CDN_SELCHANGE.
     void MSWOnSelChange(WXHWND hDlg);
 
+    // called from the hook procedure on CDN_TYPECHANGE.
+    void MSWOnTypeChange(WXHWND hDlg, int nFilterIndex);
+
 protected:
 
     virtual void DoMoveWindow(int x, int y, int width, int height) wxOVERRIDE;
diff --git a/interface/wx/filedlg.h b/interface/wx/filedlg.h
index 719ac18b7c..10715cb330 100644
--- a/interface/wx/filedlg.h
+++ b/interface/wx/filedlg.h
@@ -210,6 +210,29 @@ public:
     */
     virtual wxString GetCurrentlySelectedFilename() const;
 
+    /**
+        Returns the file type filter index currently selected in dialog.
+
+        Notice that this file type filter is not necessarily going to be the
+        one finally accepted by the user, so calling this function mostly makes
+        sense from an update UI event handler of a custom file dialog extra
+        control to update its state depending on the currently selected file
+        type filter.
+
+        Currently this function is fully implemented only under MSW and
+        always returns @c wxNOT_FOUND elsewhere.
+
+        @since 3.1.3
+
+        @return The 0-based index of the currently selected file type filter or
+            wxNOT_FOUND if nothing is selected.
+
+        @see SetExtraControlCreator()
+        @see GetFilterIndex()
+        @see SetFilterIndex()
+    */
+    virtual int GetCurrentlySelectedFilterIndex () const;
+
     /**
         Returns the default directory.
     */
diff --git a/src/common/fldlgcmn.cpp b/src/common/fldlgcmn.cpp
index 69f28d5320..2084c050ab 100644
--- a/src/common/fldlgcmn.cpp
+++ b/src/common/fldlgcmn.cpp
@@ -46,6 +46,7 @@ wxIMPLEMENT_DYNAMIC_CLASS(wxFileDialogBase, wxDialog);
 void wxFileDialogBase::Init()
 {
     m_filterIndex = 0;
+    m_currentlySelectedFilterIndex = wxNOT_FOUND;
     m_windowStyle = 0;
     m_extraControl = NULL;
     m_extraControlCreator = NULL;
diff --git a/src/msw/filedlg.cpp b/src/msw/filedlg.cpp
index 2e96f37d5c..7dc4741a45 100644
--- a/src/msw/filedlg.cpp
+++ b/src/msw/filedlg.cpp
@@ -185,6 +185,14 @@ wxFileDialogHookFunction(HWND      hDlg,
                         case CDN_SELCHANGE:
                             dialog->MSWOnSelChange((WXHWND)hDlg);
                             break;
+
+                        case CDN_TYPECHANGE:
+                            dialog->MSWOnTypeChange
+                                    (
+                                        (WXHWND)hDlg,
+                                        pNotifyCode->lpOFN->nFilterIndex
+                                    );
+                            break;
                     }
                 }
             }
@@ -350,6 +358,17 @@ void wxFileDialog::MSWOnSelChange(WXHWND hDlg)
         m_extraControl->UpdateWindowUI(wxUPDATE_UI_RECURSE);
 }
 
+void wxFileDialog::MSWOnTypeChange(WXHWND hDlg, int nFilterIndex)
+{
+    // Filter indices are 1-based, while we want to use 0-based index, as
+    // usual. However the input index can apparently also be 0 in some
+    // circumstances, so take care before decrementing it.
+    m_currentlySelectedFilterIndex = nFilterIndex ? nFilterIndex - 1 : 0;
+
+    if ( m_extraControl )
+        m_extraControl->UpdateWindowUI(wxUPDATE_UI_RECURSE);
+}
+
 // helper used below in ShowCommFileDialog(): style is used to determine
 // whether to show the "Save file" dialog (if it contains wxFD_SAVE bit) or
 // "Open file" one; returns true on success or false on failure in which case
@@ -566,6 +585,7 @@ int wxFileDialog::ShowModal()
 
     of.lpstrFilter  = filterBuffer.t_str();
     of.nFilterIndex = m_filterIndex + 1;
+    m_currentlySelectedFilterIndex = m_filterIndex;
 
     //=== Setting defaultFileName >>=========================================