diff --git a/src/cache.cc b/src/cache.cc
index ae8d42c..c8e73d7 100644
--- a/src/cache.cc
+++ b/src/cache.cc
@@ -1048,16 +1048,15 @@ typedef struct {
 /**
  * Ask for user/password and reload the page.
  */
-static void Cache_auth_callback(void *vdata)
+static void Cache_auth_callback(CacheAuthData_t *data)
 {
-   CacheAuthData_t *data = (CacheAuthData_t *)vdata;
    if (a_Auth_do_auth(data->auth, data->url))
       a_Nav_reload(data->bw);
    Cache_auth_free(data->auth);
    delete data->url;
    dFree(data);
    Cache_auth_entry(NULL, NULL);
-   a_Timeout_remove();
+   Timeout::remove();
 }
 
 /**
@@ -1079,7 +1078,7 @@ static void Cache_auth_entry(CacheEntry_t *entry, BrowserWindow *bw)
       data->url = a_Url_dup(entry->Url).release();
       data->bw = bw;
       entry->Auth = NULL;
-      a_Timeout_add(0.0, Cache_auth_callback, data);
+      Timeout::add(0.0, [=]{ Cache_auth_callback( data ); } );
    }
 }
 
@@ -1335,7 +1334,7 @@ static CacheEntry_t *Cache_process_queue(CacheEntry_t *entry)
             Cache_savelink_t *data = dNew(Cache_savelink_t, 1);
             data->bw = Client_bw;
             data->url = a_Url_dup(url).release();
-            a_Timeout_add(0.0, Cache_savelink_cb, data);
+            Timeout::add(0.0, [=]{ Cache_savelink_cb( data ); } );
          }
       }
       delete url;
@@ -1356,10 +1355,9 @@ static CacheEntry_t *Cache_process_queue(CacheEntry_t *entry)
 /**
  * Callback function for Cache_delayed_process_queue.
  */
-static void Cache_delayed_process_queue_callback(void *ptr)
+static void Cache_delayed_process_queue_callback()
 {
    CacheEntry_t *entry;
-   (void) ptr; /* Unused */
 
    while ((entry = (CacheEntry_t *)dList_nth_data(DelayedQueue, 0))) {
       Cache_ref_data(entry);
@@ -1369,7 +1367,7 @@ static void Cache_delayed_process_queue_callback(void *ptr)
       }
    }
    DelayedQueueIdleId = 0;
-   a_Timeout_remove();
+   Timeout::remove();
 }
 
 /**
@@ -1383,7 +1381,7 @@ static void Cache_delayed_process_queue(CacheEntry_t *entry)
 
    if (DelayedQueueIdleId == 0) {
       _MSG("  Setting timeout callback\n");
-      a_Timeout_add(0.0, Cache_delayed_process_queue_callback, NULL);
+      Timeout::add(0.0, []{ Cache_delayed_process_queue_callback(); } );
       DelayedQueueIdleId = 1;
    }
 }
diff --git a/src/menu.cc b/src/menu.cc
index 90c6c62..027649a 100644
--- a/src/menu.cc
+++ b/src/menu.cc
@@ -78,9 +78,9 @@ static void filemenu_cb(Fl_Widget*, void *data)
    } else if (strcmp((char*)data, "ou") == 0) {
       a_UIcmd_focus_location(popup_bw);
    } else if (strcmp((char*)data, "cw") == 0) {
-      a_Timeout_add(0.0, a_UIcmd_close_bw, popup_bw);
+      Timeout::add(0.0, [=]{ a_UIcmd_close_bw( popup_bw ); } );
    } else if (strcmp((char*)data, "ed") == 0) {
-      a_Timeout_add(0.0, a_UIcmd_close_all_bw, NULL);
+      Timeout::add(0.0, [=]{ a_UIcmd_close_all_bw( nullptr ); } );
    }
 }
 
@@ -330,7 +330,7 @@ static void Menu_simple_popup_cb(void *data)
 
    if (m && m->callback())
       m->do_callback((Fl_Widget *)data);
-   a_Timeout_remove();
+   Timeout::remove();
 }
 
 static void Menu_popup_cb(void *data)
@@ -346,7 +346,7 @@ static void Menu_popup_cb(void *data)
       if (picked->callback())
          picked->do_callback((Fl_Widget *)(d->menu));
    }
-   a_Timeout_remove();
+   Timeout::remove();
 }
 
 /**
@@ -427,7 +427,7 @@ void a_Menu_page_popup(BrowserWindow *bw, const DilloUrl *url,
    }
    pm[3].user_data(popup_url.get());
 
-   a_Timeout_add(0.0, Menu_popup_cb, (void*)&page_data);
+   Timeout::add(0.0, [&]{ Menu_popup_cb( &page_data ); } );
 }
 
 static Fl_Menu_Item link_menu_[] = {
@@ -558,7 +558,7 @@ void a_Menu_link_popup(BrowserWindow *bw, const DilloUrl *url, const DilloUrl *p
 
    Menu_set_link_menu_user_data(popup_url.get(), page_url);
 
-   a_Timeout_add(0.0, Menu_popup_cb, (void*)&link_data);
+   Timeout::add(0.0, [&]{ Menu_popup_cb( &link_data ); } );
 }
 
 /**
@@ -616,7 +616,7 @@ void a_Menu_image_popup(BrowserWindow *bw, const DilloUrl *url,
       pm[7].deactivate();
    }
 
-   a_Timeout_add(0.0, Menu_popup_cb, (void*)&image_data);
+   Timeout::add(0.0, [&]{ Menu_popup_cb( &image_data ); } );
 }
 
 /**
@@ -643,7 +643,7 @@ void a_Menu_form_popup(BrowserWindow *bw, const DilloUrl *page_url,
    hiddens_visible = hidvis;
    pm[2].label(hiddens_visible ? "Hide hiddens": "Show hiddens");
 
-   a_Timeout_add(0.0, Menu_popup_cb, (void*)&form_data);
+   Timeout::add(0.0, [&]{ Menu_popup_cb( &form_data ); } );
 }
 
 /**
@@ -675,7 +675,7 @@ void a_Menu_file_popup(BrowserWindow *bw, void *v_wid)
    popup_url.reset();
 
    //pm->label(wid->visible() ? NULL : "File");
-   a_Timeout_add(0.0, Menu_simple_popup_cb, (void*)pm);
+   Timeout::add(0.0, [=]{ Menu_simple_popup_cb( pm ); } );
 }
 
 /**
@@ -698,7 +698,7 @@ void a_Menu_bugmeter_popup(BrowserWindow *bw, const DilloUrl *url)
    popup_bw = bw;
    popup_url = a_Url_dup(url);
 
-   a_Timeout_add(0.0, Menu_simple_popup_cb, (void*)pm);
+   Timeout::add(0.0, [=]{ Menu_simple_popup_cb( pm ); } );
 }
 
 /**
@@ -735,7 +735,7 @@ void a_Menu_history_popup(BrowserWindow *bw, int x, int y, int direction)
       pm[i].label(FL_NORMAL_LABEL, a_History_get_title(history_list[i], 1));
       pm[i].callback(Menu_history_cb, INT2VOIDP(i+1));
    }
-   a_Timeout_add(0.0, Menu_simple_popup_cb, (void*)pm);
+   Timeout::add(0.0, [=]{ Menu_simple_popup_cb( pm ); } );
 }
 
 /**
diff --git a/src/nav.cc b/src/nav.cc
index fc2e878..7d024b5 100644
--- a/src/nav.cc
+++ b/src/nav.cc
@@ -362,11 +362,11 @@ static void Nav_repush(BrowserWindow *bw)
    }
 }
 
-static void Nav_repush_callback(void *data)
+static void Nav_repush_callback(BrowserWindow *data)
 {
    _MSG(">>>> Nav_repush_callback <<<<\n");
-   Nav_repush(reinterpret_cast< BrowserWindow * >( data ));
-   a_Timeout_remove();
+   Nav_repush( data );
+   Timeout::remove();
 }
 
 /*
@@ -381,15 +381,14 @@ void a_Nav_repush(BrowserWindow *bw)
 {
    dReturn_if_fail (bw != NULL);
    MSG(">>>> a_Nav_repush <<<<\n");
-   a_Timeout_add(0.0, Nav_repush_callback, (void*)bw);
+   Timeout::add(0.0, [bw] { Nav_repush_callback( bw ); } );
 }
 
 /*
  * This one does a_Nav_redirection0's job.
  */
-static void Nav_redirection0_callback(void *data)
+static void Nav_redirection0_callback(BrowserWindow *bw)
 {
-   BrowserWindow *bw = (BrowserWindow *)data;
    const DilloUrl *referer_url = a_History_get_url(NAV_TOP_UIDX(bw));
    _MSG(">>>> Nav_redirection0_callback <<<<\n");
 
@@ -399,7 +398,7 @@ static void Nav_redirection0_callback(void *data)
    }
    bw->meta_refresh_url.reset();
    bw->meta_refresh_status = 0;
-   a_Timeout_remove();
+   Timeout::remove();
 }
 
 /*
@@ -414,7 +413,7 @@ void a_Nav_redirection0(BrowserWindow *bw, const DilloUrl *new_url)
    a_Url_set_flags(bw->meta_refresh_url.get(),
                    URL_FLAGS(new_url)|URL_E2EQuery|URL_IgnoreScroll);
    bw->meta_refresh_status = 2;
-   a_Timeout_add(0.0, Nav_redirection0_callback, (void*)bw);
+   Timeout::add(0.0, [=] { Nav_redirection0_callback( bw); } );
 }
 
 /*
@@ -456,9 +455,8 @@ void a_Nav_home(BrowserWindow *bw)
 /*
  * This one does a_Nav_reload's job!
  */
-static void Nav_reload_callback(void *data)
+static void Nav_reload_callback(BrowserWindow *bw)
 {
-   BrowserWindow *bw = reinterpret_cast< BrowserWindow * >( data );
    const DilloUrl *h_url;
    int choice, confirmed = 1;
 
@@ -499,7 +497,7 @@ static void Nav_reload_callback(void *data)
 void a_Nav_reload(BrowserWindow *bw)
 {
    dReturn_if_fail (bw != NULL);
-   a_Timeout_add(0.0, Nav_reload_callback, (void*)bw);
+   Timeout::add(0.0, [=]{ Nav_reload_callback( bw ); } );
 }
 
 /*
diff --git a/src/timeout.cc b/src/timeout.cc
index 0c017a6..d90e2a3 100644
--- a/src/timeout.cc
+++ b/src/timeout.cc
@@ -16,29 +16,47 @@
 #include <FL/Fl.H>
 #include "timeout.hh"
 
+#include <memory>
+
 // C++ functions with C linkage ----------------------------------------------
 
+namespace
+{
+	void
+	doCallback( void *const v_func_p )
+	{
+		std::unique_ptr< Timeout::Cb_t > func_p{ reinterpret_cast< Timeout::Cb_t * >( v_func_p ) };
+		auto &func= *func_p;
+
+		func();
+	}
+}
+
 /**
  * Hook a one-time timeout function 'cb' after 't' seconds
  * with 'cbdata" as its data.
  */
-void a_Timeout_add(float t, TimeoutCb_t cb, void *cbdata)
+void
+Timeout::add( const float t, Cb_t cb )
 {
-   Fl::add_timeout(t, cb, cbdata);
+   auto ownership= std::make_unique< Cb_t >( cb );
+   Fl::add_timeout( t, doCallback, ownership.release() );
 }
 
 /**
  * To be called from inside the 'cb' function when it wants to keep running
  */
-void a_Timeout_repeat(float t, TimeoutCb_t cb, void *cbdata)
+void
+Timeout::repeat( const float t, Cb_t cb )
 {
-   Fl::add_timeout(t, cb, cbdata);
+   auto ownership= std::make_unique< Cb_t >( cb );
+   Fl::repeat_timeout( t, doCallback, ownership.release() );
 }
 
 /**
  * Stop running a timeout function
  */
-void a_Timeout_remove()
+void Timeout::remove()
 {
    /* in FLTK, timeouts run one time by default */
 }
diff --git a/src/timeout.hh b/src/timeout.hh
index 17a3e7b..8d58d0b 100644
--- a/src/timeout.hh
+++ b/src/timeout.hh
@@ -1,20 +1,18 @@
+static_assert( __cplusplus >= 2023'02 );
 #ifndef __TIMEOUT_HH__
 #define __TIMEOUT_HH__
 
-#ifdef __cplusplus
-extern "C" {
-#endif /* __cplusplus */
+#include <functional>
 
-typedef void (*TimeoutCb_t)(void *data);
+namespace Timeout
+{
+	using Cb_t= std::function< void () >;
 
-void a_Timeout_add(float t, TimeoutCb_t cb, void *cbdata);
-void a_Timeout_repeat(float t, TimeoutCb_t cb, void *cbdata);
-void a_Timeout_remove(void);
-
-
-#ifdef __cplusplus
+	void add( float t, Cb_t cb );
+	void repeat( float t, Cb_t cb );
+	void remove();
 }
-#endif /* __cplusplus */
+
 
 #endif /* __TIMEOUT_HH__ */
 
diff --git a/src/uicmd.cc b/src/uicmd.cc
index 693be29..a5d0dfe 100644
--- a/src/uicmd.cc
+++ b/src/uicmd.cc
@@ -255,7 +255,7 @@ int CustTabs::handle(int e)
          a_UIcmd_open_url_nw(bw, NULL);
          ret = 1;
       } else if (cmd == KEYS_CLOSE_ALL) {
-         a_Timeout_add(0.0, a_UIcmd_close_all_bw, NULL);
+         Timeout::add(0.0, []{ a_UIcmd_close_all_bw( nullptr ); } );
          ret = 1;
       }
    } else if (e == FL_MOUSEWHEEL && prefs.scroll_switches_tabs) {
@@ -540,7 +540,7 @@ static void win_cb (Fl_Widget *w, void *cb_data) {
 /*
  * Given a UI or UI child widget, return its bw.
  */
-BrowserWindow *a_UIcmd_get_bw_by_widget(void *v_wid)
+BrowserWindow *a_UIcmd::a_UIcmd_get_bw_by_widget(void *v_wid)
 {
    BrowserWindow *bw;
    for (int i = 0; i < a_Bw_num(); ++i) {
@@ -556,7 +556,7 @@ BrowserWindow *a_UIcmd_get_bw_by_widget(void *v_wid)
  * Create a new UI and its associated BrowserWindow data structure.
  * Use style from v_ui. If non-NULL it must be of type UI*.
  */
-BrowserWindow *a_UIcmd_browser_window_new(int ww, int wh,
+BrowserWindow *a_UIcmd::a_UIcmd_browser_window_new(int ww, int wh,
                                           uint32_t xid, const void *vbw)
 {
    BrowserWindow *old_bw = (BrowserWindow*)vbw;
@@ -672,9 +672,8 @@ static BrowserWindow *UIcmd_tab_new(CustTabs *tabs, UI *old_ui, int focus)
 /*
  * Close one browser window
  */
-void a_UIcmd_close_bw(void *vbw)
+void a_UIcmd::a_UIcmd_close_bw(BrowserWindow *bw)
 {
-   BrowserWindow *bw = (BrowserWindow *)vbw;
    UI *ui = BW2UI(bw);
    CustTabs *tabs = ui->tabs();
    Layout *layout = (Layout*)bw->render_layout;
@@ -711,7 +710,7 @@ void a_UIcmd_close_bw(void *vbw)
 /*
  * Close all the browser windows
  */
-void a_UIcmd_close_all_bw(void *)
+void a_UIcmd::a_UIcmd_close_all_bw(void *)
 {
    BrowserWindow *bw;
    int choice = 1;
@@ -722,7 +721,7 @@ void a_UIcmd_close_all_bw(void *)
                                "Quit", "Cancel", NULL);
    if (choice == 1)
       while ((bw = a_Bw_get(0)))
-         a_UIcmd_close_bw((void*)bw);
+         a_UIcmd_close_bw(bw);
 }
 
 /*
@@ -757,13 +756,12 @@ static char *UIcmd_find_search_str(const char *str)
  *
  * our custom "file:" URIs are normalized here too.
  */
-void a_UIcmd_open_urlstr(void *vbw, const char *urlstr)
+void a_UIcmd::a_UIcmd_open_urlstr(BrowserWindow *bw, const char *urlstr)
 {
    char *new_urlstr;
    char *search_urlstr = NULL;
    DilloUrl *url;
    int ch;
-   BrowserWindow *bw = (BrowserWindow*)vbw;
 
    if ((search_urlstr = UIcmd_find_search_str(urlstr))) {
       urlstr = search_urlstr;
@@ -798,7 +796,7 @@ void a_UIcmd_open_urlstr(void *vbw, const char *urlstr)
 /*
  * Open a new URL in the given browser window
  */
-void a_UIcmd_open_url(BrowserWindow *bw, const DilloUrl *url)
+void a_UIcmd::a_UIcmd_open_url(BrowserWindow *bw, const DilloUrl *url)
 {
    if (url) {
       a_Nav_push(bw, url, NULL);
@@ -833,7 +831,7 @@ static void UIcmd_open_url_nbw(BrowserWindow *new_bw, const DilloUrl *url)
 /*
  * Open a new URL in a new browser window
  */
-void a_UIcmd_open_url_nw(BrowserWindow *bw, const DilloUrl *url)
+void a_UIcmd::a_UIcmd_open_url_nw(BrowserWindow *bw, const DilloUrl *url)
 {
    int w, h;
    BrowserWindow *new_bw;
@@ -849,9 +847,8 @@ void a_UIcmd_open_url_nw(BrowserWindow *bw, const DilloUrl *url)
 /*
  * Open a new URL in a new tab in the same browser window
  */
-void a_UIcmd_open_url_nt(void *vbw, const DilloUrl *url, int focus)
+void a_UIcmd::a_UIcmd_open_url_nt(BrowserWindow *bw, const DilloUrl *url, int focus)
 {
-   BrowserWindow *bw = (BrowserWindow *)vbw;
    BrowserWindow *new_bw = UIcmd_tab_new(BW2UI(bw)->tabs(),
                                          bw ? BW2UI(bw) : NULL, focus);
    /* Preserve same zoom factor in new tab */
@@ -862,7 +859,7 @@ void a_UIcmd_open_url_nt(void *vbw, const DilloUrl *url, int focus)
 /*
  * Send the browser back to previous page
  */
-void a_UIcmd_back(void *vbw)
+void a_UIcmd::a_UIcmd_back(void *vbw)
 {
    a_Nav_back((BrowserWindow*)vbw);
 }
@@ -870,7 +867,7 @@ void a_UIcmd_back(void *vbw)
 /*
  * Popup the navigation menu of the Back button
  */
-void a_UIcmd_back_popup(void *vbw, int x, int y)
+void a_UIcmd::a_UIcmd_back_popup(void *vbw, int x, int y)
 {
    a_Menu_history_popup((BrowserWindow*)vbw, x, y, -1);
 }
@@ -878,7 +875,7 @@ void a_UIcmd_back_popup(void *vbw, int x, int y)
 /*
  * Send the browser to next page in the history list
  */
-void a_UIcmd_forw(void *vbw)
+void a_UIcmd::a_UIcmd_forw(void *vbw)
 {
    a_Nav_forw((BrowserWindow*)vbw);
 }
@@ -886,7 +883,7 @@ void a_UIcmd_forw(void *vbw)
 /*
  * Popup the navigation menu of the Forward button
  */
-void a_UIcmd_forw_popup(void *vbw, int x, int y)
+void a_UIcmd::a_UIcmd_forw_popup(void *vbw, int x, int y)
 {
    a_Menu_history_popup((BrowserWindow*)vbw, x, y, 1);
 }
@@ -894,7 +891,7 @@ void a_UIcmd_forw_popup(void *vbw, int x, int y)
 /*
  * Send the browser to home URL
  */
-void a_UIcmd_home(void *vbw)
+void a_UIcmd::a_UIcmd_home(void *vbw)
 {
    a_UIcmd_open_url((BrowserWindow*)vbw, prefs.home);
 }
@@ -902,7 +899,7 @@ void a_UIcmd_home(void *vbw)
 /*
  * Reload current URL
  */
-void a_UIcmd_reload(void *vbw)
+void a_UIcmd::a_UIcmd_reload(void *vbw)
 {
    a_Nav_reload((BrowserWindow*)vbw);
 }
@@ -910,7 +907,7 @@ void a_UIcmd_reload(void *vbw)
 /*
  * Reload all active tabs
  */
-void a_UIcmd_reload_all_active()
+void a_UIcmd::a_UIcmd_reload_all_active()
 {
    struct Tabgroup *tg = tabgroups;
    for (tg = tabgroups; tg; tg = tg->next) {
@@ -923,7 +920,7 @@ void a_UIcmd_reload_all_active()
 /*
  * Repush current URL
  */
-void a_UIcmd_repush(void *vbw)
+void a_UIcmd::a_UIcmd_repush(void *vbw)
 {
    a_Nav_repush((BrowserWindow*)vbw);
 }
@@ -931,7 +928,7 @@ void a_UIcmd_repush(void *vbw)
 /*
  * Zero-delay URL redirection.
  */
-void a_UIcmd_redirection0(void *vbw, const DilloUrl *url)
+void a_UIcmd::a_UIcmd_redirection0(void *vbw, const DilloUrl *url)
 {
    a_Nav_redirection0((BrowserWindow*)vbw, url);
 }
@@ -939,7 +936,7 @@ void a_UIcmd_redirection0(void *vbw, const DilloUrl *url)
 /*
  * Zoom in
  */
-void a_UIcmd_zoom_in(void *vbw)
+void a_UIcmd::a_UIcmd_zoom_in(void *vbw)
 {
    BrowserWindow *bw = (BrowserWindow*) vbw;
    bw->zoom += 0.10;
@@ -955,7 +952,7 @@ void a_UIcmd_zoom_in(void *vbw)
 /*
  * Zoom out
  */
-void a_UIcmd_zoom_out(void *vbw)
+void a_UIcmd::a_UIcmd_zoom_out(void *vbw)
 {
    BrowserWindow *bw = (BrowserWindow*) vbw;
    bw->zoom -= 0.10;
@@ -971,7 +968,7 @@ void a_UIcmd_zoom_out(void *vbw)
 /*
  * Zoom reset
  */
-void a_UIcmd_zoom_reset(void *vbw)
+void a_UIcmd::a_UIcmd_zoom_reset(void *vbw)
 {
    BrowserWindow *bw = (BrowserWindow*) vbw;
    bw->zoom = 1.0;
@@ -1034,7 +1031,7 @@ static char *UIcmd_make_save_filename(const DilloUrl *url)
 /*
  * Set the default directory for saving files.
  */
-void a_UIcmd_init(void)
+void a_UIcmd::a_UIcmd_init(void)
 {
    const char *dir = prefs.save_dir;
 
@@ -1107,7 +1104,7 @@ static void UIcmd_save(BrowserWindow *bw, const DilloUrl *url,
 /*
  * Save current URL
  */
-void a_UIcmd_save(void *vbw)
+void a_UIcmd::a_UIcmd_save(void *vbw)
 {
    BrowserWindow *bw = (BrowserWindow *)vbw;
    const DilloUrl *url = a_History_get_url(NAV_TOP_UIDX(bw));
@@ -1120,7 +1117,7 @@ void a_UIcmd_save(void *vbw)
 /*
  * Select a file
  */
-const char *a_UIcmd_select_file()
+const char *a_UIcmd::a_UIcmd_select_file()
 {
    return a_Dialog_select_file("Flenser: Select a File", NULL, NULL);
 }
@@ -1129,7 +1126,7 @@ const char *a_UIcmd_select_file()
  * Stop network activity on this bw.
  * The stop button was pressed: stop page (and images) downloads.
  */
-void a_UIcmd_stop(void *vbw)
+void a_UIcmd::a_UIcmd_stop(void *vbw)
 {
    BrowserWindow *bw = (BrowserWindow *)vbw;
 
@@ -1142,7 +1139,7 @@ void a_UIcmd_stop(void *vbw)
 /*
  * Popup the tools menu
  */
-void a_UIcmd_tools(void *vbw, int x, int y)
+void a_UIcmd::a_UIcmd_tools(void *vbw, int x, int y)
 {
    a_Menu_tools_popup((BrowserWindow*)vbw, x, y);
 }
@@ -1150,7 +1147,7 @@ void a_UIcmd_tools(void *vbw, int x, int y)
 /*
  * Open URL with dialog chooser
  */
-void a_UIcmd_open_file(void *vbw)
+void a_UIcmd::a_UIcmd_open_file(void *vbw)
 {
    auto name = a_Dialog_open_file("Flenser: Open File", std::nullopt, "");
 
@@ -1200,13 +1197,13 @@ static char *UIcmd_make_search_str(const char *str)
 /*
  * Get a query from a dialog and open it
  */
-void a_UIcmd_search_dialog(void *vbw)
+void a_UIcmd::a_UIcmd_search_dialog(BrowserWindow *bw)
 {
    const char *query;
 
    if ((query = a_Dialog_input("Flenser: Search", "Search the Web:"))) {
       char *url_str = UIcmd_make_search_str(query);
-      a_UIcmd_open_urlstr(vbw, url_str);
+      a_UIcmd_open_urlstr(bw, url_str);
       dFree(url_str);
    }
 }
@@ -1214,7 +1211,7 @@ void a_UIcmd_search_dialog(void *vbw)
 /*
  * Get password for user
  */
-const char *a_UIcmd_get_passwd(const char *user)
+const char *a_UIcmd::a_UIcmd_get_passwd(const char *user)
 {
    const char *passwd;
    const char *title = "Flenser: Password";
@@ -1227,7 +1224,7 @@ const char *a_UIcmd_get_passwd(const char *user)
 /*
  * Save link URL
  */
-void a_UIcmd_save_link(BrowserWindow *bw, const DilloUrl *url)
+void a_UIcmd::a_UIcmd_save_link(BrowserWindow *bw, const DilloUrl *url)
 {
    UIcmd_save(bw, url, "Flenser: Save Link as File");
 }
@@ -1235,7 +1232,7 @@ void a_UIcmd_save_link(BrowserWindow *bw, const DilloUrl *url)
 /*
  * Request the bookmarks page
  */
-void a_UIcmd_book(void *vbw)
+void a_UIcmd::a_UIcmd_book(void *vbw)
 {
    auto url = a_Url_new("dpi:/bm/", NULL);
    a_UIcmd_open_url((BrowserWindow*)vbw, url.get());
@@ -1244,7 +1241,7 @@ void a_UIcmd_book(void *vbw)
 /*
  * Add a bookmark for a certain URL
  */
-void a_UIcmd_add_bookmark(BrowserWindow *bw, const DilloUrl *url)
+void a_UIcmd::a_UIcmd_add_bookmark(BrowserWindow *bw, const DilloUrl *url)
 {
    a_Bookmarks_add(bw, url);
 }
@@ -1253,7 +1250,7 @@ void a_UIcmd_add_bookmark(BrowserWindow *bw, const DilloUrl *url)
 /*
  * Popup the page menu
  */
-void a_UIcmd_page_popup(void *vbw, bool_t has_bugs, std::vector< std::unique_ptr< DilloUrl > > *cssUrls)
+void a_UIcmd::a_UIcmd_page_popup(void *vbw, bool_t has_bugs, std::vector< std::unique_ptr< DilloUrl > > *cssUrls)
 {
    BrowserWindow *bw = (BrowserWindow*)vbw;
    const DilloUrl *url = a_History_get_url(NAV_TOP_UIDX(bw));
@@ -1263,7 +1260,7 @@ void a_UIcmd_page_popup(void *vbw, bool_t has_bugs, std::vector< std::unique_ptr
 /*
  * Popup the link menu
  */
-void a_UIcmd_link_popup(void *vbw, const DilloUrl *url, const DilloUrl *page_url)
+void a_UIcmd::a_UIcmd_link_popup(void *vbw, const DilloUrl *url, const DilloUrl *page_url)
 {
    a_Menu_link_popup((BrowserWindow*)vbw, url, page_url);
 }
@@ -1271,7 +1268,7 @@ void a_UIcmd_link_popup(void *vbw, const DilloUrl *url, const DilloUrl *page_url
 /*
  * Pop up the image menu
  */
-void a_UIcmd_image_popup(void *vbw, const DilloUrl *url, bool_t loaded_img,
+void a_UIcmd::a_UIcmd_image_popup(void *vbw, const DilloUrl *url, bool_t loaded_img,
                          DilloUrl *page_url, DilloUrl *link_url)
 {
    a_Menu_image_popup((BrowserWindow*)vbw, url, loaded_img, page_url,link_url);
@@ -1280,7 +1277,7 @@ void a_UIcmd_image_popup(void *vbw, const DilloUrl *url, bool_t loaded_img,
 /*
  * Pop up the form menu
  */
-void a_UIcmd_form_popup(void *vbw, const DilloUrl *url, void *vform,
+void a_UIcmd::a_UIcmd_form_popup(void *vbw, const DilloUrl *url, void *vform,
                         bool_t showing_hiddens)
 {
    a_Menu_form_popup((BrowserWindow*)vbw, url, vform, showing_hiddens);
@@ -1289,7 +1286,7 @@ void a_UIcmd_form_popup(void *vbw, const DilloUrl *url, void *vform,
 /*
  * Pop up the file menu
  */
-void a_UIcmd_file_popup(void *vbw, void *v_wid)
+void a_UIcmd::a_UIcmd_file_popup(void *vbw, void *v_wid)
 {
    a_Menu_file_popup((BrowserWindow*)vbw, v_wid);
 }
@@ -1297,7 +1294,7 @@ void a_UIcmd_file_popup(void *vbw, void *v_wid)
 /*
  * Copy url string to paste buffer
  */
-void a_UIcmd_copy_urlstr(BrowserWindow *bw, const char *urlstr)
+void a_UIcmd::a_UIcmd_copy_urlstr(BrowserWindow *bw, const char *urlstr)
 {
    Layout *layout = (Layout*)bw->render_layout;
    layout->copySelection(urlstr);
@@ -1306,7 +1303,7 @@ void a_UIcmd_copy_urlstr(BrowserWindow *bw, const char *urlstr)
 /*
  * Ask the vsource dpi to show this URL's source
  */
-void a_UIcmd_view_page_source(BrowserWindow *bw, const DilloUrl *url)
+void a_UIcmd::a_UIcmd_view_page_source(BrowserWindow *bw, const DilloUrl *url)
 {
    char *buf, *major;
    int buf_size;
@@ -1339,10 +1336,8 @@ void a_UIcmd_view_page_source(BrowserWindow *bw, const DilloUrl *url)
 /*
  * Show the browser window's HTML errors in a text window
  */
-void a_UIcmd_view_page_bugs(void *vbw)
+void a_UIcmd::a_UIcmd_view_page_bugs(BrowserWindow *bw)
 {
-   BrowserWindow *bw = (BrowserWindow*)vbw;
-
    if (bw->num_page_bugs > 0) {
       a_Dialog_text_window("Flenser: Detected HTML errors", bw->page_bugs.c_str());
    } else {
@@ -1353,10 +1348,8 @@ void a_UIcmd_view_page_bugs(void *vbw)
 /*
  * Popup the bug meter menu
  */
-void a_UIcmd_bugmeter_popup(void *vbw)
+void a_UIcmd::a_UIcmd_bugmeter_popup(BrowserWindow *bw)
 {
-   BrowserWindow *bw = (BrowserWindow*)vbw;
-
    a_Menu_bugmeter_popup(bw, a_History_get_url(NAV_TOP_UIDX(bw)));
 }
 
@@ -1364,7 +1357,7 @@ void a_UIcmd_bugmeter_popup(void *vbw)
  * Make a list of URL indexes for the history popup
  * based on direction (-1 = back, 1 = forward)
  */
-int *a_UIcmd_get_history(BrowserWindow *bw, int direction)
+int *a_UIcmd::a_UIcmd_get_history(BrowserWindow *bw, int direction)
 {
    int i, j, n;
    int *hlist;
@@ -1388,7 +1381,7 @@ int *a_UIcmd_get_history(BrowserWindow *bw, int direction)
 /*
  * Jump to a certain URL in the navigation stack.
  */
-void a_UIcmd_nav_jump(BrowserWindow *bw, int offset, int new_bw)
+void a_UIcmd::a_UIcmd_nav_jump(BrowserWindow *bw, int offset, int new_bw)
 {
    a_Nav_jump(bw, offset, new_bw);
 }
@@ -1398,7 +1391,7 @@ void a_UIcmd_nav_jump(BrowserWindow *bw, int offset, int new_bw)
 /*
  * Return browser window width and height
  */
-void a_UIcmd_get_wh(BrowserWindow *bw, int *w, int *h)
+void a_UIcmd::a_UIcmd_get_wh(BrowserWindow *bw, int *w, int *h)
 {
    *w = BW2UI(bw)->w();
    *h = BW2UI(bw)->h();
@@ -1408,7 +1401,7 @@ void a_UIcmd_get_wh(BrowserWindow *bw, int *w, int *h)
 /*
  * Get the scroll position (x, y offset pair)
  */
-void a_UIcmd_get_scroll_xy(BrowserWindow *bw, int *x, int *y)
+void a_UIcmd::a_UIcmd_get_scroll_xy(BrowserWindow *bw, int *x, int *y)
 {
    Layout *layout = (Layout*)bw->render_layout;
 
@@ -1421,7 +1414,7 @@ void a_UIcmd_get_scroll_xy(BrowserWindow *bw, int *x, int *y)
 /*
  * Set the scroll position ({x, y} offset pair)
  */
-void a_UIcmd_set_scroll_xy(BrowserWindow *bw, int x, int y)
+void a_UIcmd::a_UIcmd_set_scroll_xy(BrowserWindow *bw, int x, int y)
 {
    Layout *layout = (Layout*)bw->render_layout;
 
@@ -1433,7 +1426,7 @@ void a_UIcmd_set_scroll_xy(BrowserWindow *bw, int x, int y)
 /*
  * Set the scroll position by fragment (from URL)
  */
-void a_UIcmd_set_scroll_by_fragment(BrowserWindow *bw, const char *f)
+void a_UIcmd::a_UIcmd_set_scroll_by_fragment(BrowserWindow *bw, const char *f)
 {
    Layout *layout = (Layout*)bw->render_layout;
 
@@ -1445,7 +1438,7 @@ void a_UIcmd_set_scroll_by_fragment(BrowserWindow *bw, const char *f)
 /*
  * Pass scrolling command to dw.
  */
-void a_UIcmd_scroll(BrowserWindow *bw, int icmd)
+void a_UIcmd::a_UIcmd_scroll(BrowserWindow *bw, int icmd)
 {
    Layout *layout = (Layout*)bw->render_layout;
 
@@ -1481,7 +1474,7 @@ void a_UIcmd_scroll(BrowserWindow *bw, int icmd)
 /*
  * Get location's text
  */
-char *a_UIcmd_get_location_text(BrowserWindow *bw)
+char *a_UIcmd::a_UIcmd_get_location_text(BrowserWindow *bw)
 {
    return dStrdup(BW2UI(bw)->get_location());
 }
@@ -1489,7 +1482,7 @@ char *a_UIcmd_get_location_text(BrowserWindow *bw)
 /*
  * Set location's text
  */
-void a_UIcmd_set_location_text(void *vbw, const char *text)
+void a_UIcmd::a_UIcmd_set_location_text(void *vbw, const char *text)
 {
    BrowserWindow *bw = (BrowserWindow*)vbw;
    BW2UI(bw)->set_location(text);
@@ -1499,7 +1492,7 @@ void a_UIcmd_set_location_text(void *vbw, const char *text)
  * Set the page progress bar
  * cmd: 0 Deactivate, 1 Update, 2 Clear
  */
-void a_UIcmd_set_page_prog(BrowserWindow *bw, size_t nbytes, int cmd)
+void a_UIcmd::a_UIcmd_set_page_prog(BrowserWindow *bw, size_t nbytes, int cmd)
 {
    BW2UI(bw)->set_page_prog(nbytes, cmd);
 }
@@ -1508,7 +1501,7 @@ void a_UIcmd_set_page_prog(BrowserWindow *bw, size_t nbytes, int cmd)
  * Set the images progress bar
  * cmd: 0 Deactivate, 1 Update, 2 Clear
  */
-void a_UIcmd_set_img_prog(BrowserWindow *bw, int n_img, int t_img, int cmd)
+void a_UIcmd::a_UIcmd_set_img_prog(BrowserWindow *bw, int n_img, int t_img, int cmd)
 {
    BW2UI(bw)->set_img_prog(n_img, t_img, cmd);
 #if 0
@@ -1520,7 +1513,7 @@ void a_UIcmd_set_img_prog(BrowserWindow *bw, int n_img, int t_img, int cmd)
 /*
  * Set the bug meter progress label
  */
-void a_UIcmd_set_bug_prog(BrowserWindow *bw, int n_bug)
+void a_UIcmd::a_UIcmd_set_bug_prog(BrowserWindow *bw, int n_bug)
 {
    BW2UI(bw)->set_bug_prog(n_bug);
 }
@@ -1529,7 +1522,7 @@ void a_UIcmd_set_bug_prog(BrowserWindow *bw, int n_bug)
  * Set the page title in the tab label and window titlebar.
  * (Update window titlebar for the current tab only)
  */
-void a_UIcmd_set_page_title(BrowserWindow *bw, const char *label)
+void a_UIcmd::a_UIcmd_set_page_title(BrowserWindow *bw, const char *label)
 {
    const int size = 128;
    char title[size];
@@ -1552,7 +1545,7 @@ void a_UIcmd_set_page_title(BrowserWindow *bw, const char *label)
  * Beware: The safe way to set an arbitrary string is
  *         a_UIcmd_set_msg(bw, "%s", str)
  */
-void a_UIcmd_set_msg(BrowserWindow *bw, const char *format, ...)
+void a_UIcmd::a_UIcmd_set_msg(BrowserWindow *bw, const char *format, ...)
 {
    va_list argp;
    Dstr *ds = dStr_sized_new(128);
@@ -1566,7 +1559,7 @@ void a_UIcmd_set_msg(BrowserWindow *bw, const char *format, ...)
 /*
  * Set the sensitivity of back/forw/stop buttons.
  */
-void a_UIcmd_set_buttons_sens(BrowserWindow *bw)
+void a_UIcmd::a_UIcmd_set_buttons_sens(BrowserWindow *bw)
 {
    int sens;
 
@@ -1585,7 +1578,7 @@ void a_UIcmd_set_buttons_sens(BrowserWindow *bw)
 /*
  * Toggle control panel
  */
-void a_UIcmd_panels_toggle(BrowserWindow *bw)
+void a_UIcmd::a_UIcmd_panels_toggle(BrowserWindow *bw)
 {
    BW2UI(bw)->panels_toggle();
 }
@@ -1593,7 +1586,7 @@ void a_UIcmd_panels_toggle(BrowserWindow *bw)
 /*
  * Search for next/previous occurrence of key.
  */
-void a_UIcmd_findtext_search(BrowserWindow *bw, const char *key,
+void a_UIcmd::a_UIcmd_findtext_search(BrowserWindow *bw, const char *key,
                              int case_sens, int backward)
 {
    Layout *l = (Layout *)bw->render_layout;
@@ -1615,7 +1608,7 @@ void a_UIcmd_findtext_search(BrowserWindow *bw, const char *key,
 /*
  * Reset text search state.
  */
-void a_UIcmd_findtext_reset(BrowserWindow *bw)
+void a_UIcmd::a_UIcmd_findtext_reset(BrowserWindow *bw)
 {
    Layout *l = (Layout *)bw->render_layout;
    l->resetSearch();
@@ -1626,7 +1619,7 @@ void a_UIcmd_findtext_reset(BrowserWindow *bw)
 /*
  * Tell the UI to hide/show the findbar
  */
-void a_UIcmd_findbar_toggle(BrowserWindow *bw, int on)
+void a_UIcmd::a_UIcmd_findbar_toggle(BrowserWindow *bw, int on)
 {
    BW2UI(bw)->findbar_toggle(on);
 }
@@ -1634,7 +1627,7 @@ void a_UIcmd_findbar_toggle(BrowserWindow *bw, int on)
 /*
  * Focus the rendered area.
  */
-void a_UIcmd_focus_main_area(BrowserWindow *bw)
+void a_UIcmd::a_UIcmd_focus_main_area(BrowserWindow *bw)
 {
    BW2UI(bw)->focus_main();
 }
@@ -1642,7 +1635,7 @@ void a_UIcmd_focus_main_area(BrowserWindow *bw)
 /*
  * Focus the location bar.
  */
-void a_UIcmd_focus_location(void *vbw)
+void a_UIcmd::a_UIcmd_focus_location(void *vbw)
 {
    BrowserWindow *bw = (BrowserWindow*)vbw;
    BW2UI(bw)->focus_location();
diff --git a/src/uicmd.hh b/src/uicmd.hh
index 65abfba..ae67b44 100644
--- a/src/uicmd.hh
+++ b/src/uicmd.hh
@@ -15,19 +15,17 @@
 
 #include "bw.hh"
 
-#ifdef __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-
+inline namespace a_UIcmd
+{
 
 BrowserWindow *a_UIcmd_browser_window_new(int ww, int wh,
                                           uint32_t xid, const void *v_bw);
 BrowserWindow *a_UIcmd_get_bw_by_widget(void *v_wid);
 void a_UIcmd_send_event_to_tabs_by_wid(int e, void *v_wid);
-void a_UIcmd_open_urlstr(void *vbw, const char *urlstr);
+void a_UIcmd_open_urlstr(BrowserWindow *bw, const char *urlstr);
 void a_UIcmd_open_url(BrowserWindow *bw, const DilloUrl *url);
 void a_UIcmd_open_url_nw(BrowserWindow *bw, const DilloUrl *url);
-void a_UIcmd_open_url_nt(void *vbw, const DilloUrl *url, int focus);
+void a_UIcmd_open_url_nt(BrowserWindow *bw, const DilloUrl *url, int focus);
 void a_UIcmd_back(void *vbw);
 void a_UIcmd_back_popup(void *vbw, int x, int y);
 void a_UIcmd_forw(void *vbw);
@@ -46,7 +44,7 @@ void a_UIcmd_tools(void *vbw, int x, int y);
 void a_UIcmd_save_link(BrowserWindow *bw, const DilloUrl *url);
 void a_UIcmd_open_file(void *vbw);
 const char *a_UIcmd_select_file(void);
-void a_UIcmd_search_dialog(void *vbw);
+void a_UIcmd_search_dialog(BrowserWindow *vbw);
 const char *a_UIcmd_get_passwd(const char *user);
 void a_UIcmd_book(void *vbw);
 void a_UIcmd_add_bookmark(BrowserWindow *bw, const DilloUrl *url);
@@ -67,12 +65,12 @@ void a_UIcmd_form_popup(void *vbw, const DilloUrl *url, void *vform,
 void a_UIcmd_file_popup(void *vbw, void *v_wid);
 void a_UIcmd_copy_urlstr(BrowserWindow *bw, const char *urlstr);
 void a_UIcmd_view_page_source(BrowserWindow *bw, const DilloUrl *url);
-void a_UIcmd_view_page_bugs(void *vbw);
-void a_UIcmd_bugmeter_popup(void *vbw);
+void a_UIcmd_view_page_bugs(BrowserWindow *bw);
+void a_UIcmd_bugmeter_popup(BrowserWindow *bw);
 int *a_UIcmd_get_history(BrowserWindow *bw, int direction);
 void a_UIcmd_nav_jump(BrowserWindow *bw, int offset, int new_bw);
 
-void a_UIcmd_close_bw(void *vbw);
+void a_UIcmd_close_bw(BrowserWindow *bw);
 void a_UIcmd_close_all_bw(void *p);
 
 void a_UIcmd_init(void);
@@ -94,8 +92,6 @@ void a_UIcmd_set_page_title(BrowserWindow *bw, const char *label);
 void a_UIcmd_set_msg(BrowserWindow *bw, const char *format, ...);
 void a_UIcmd_set_buttons_sens(BrowserWindow *bw);
 
-#ifdef __cplusplus
 }
-#endif /* __cplusplus */
 
 #endif // __UICMD_HH__