diff --git a/gtk3/main.c b/gtk3/main.c
index 2fff2da..c8378a1 100644
--- a/gtk3/main.c
+++ b/gtk3/main.c
@@ -860,6 +860,27 @@ static gboolean on_key_press(GtkWidget *w, GdkEventKey *event, gpointer data) {
 		case GDK_KEY_k: mask = BUTTON_MASK_B; break;
 		case GDK_KEY_l: mask = BUTTON_MASK_A; break;
 
+		case GDK_KEY_Tab: {
+			rewind_down = event->type == GDK_KEY_PRESS;
+			GB_set_turbo_mode(&gb, turbo_down, turbo_down && rewind_down);
+
+			if (event->type == GDK_KEY_RELEASE) {
+				rewind_paused = false;
+			}
+		break; }
+
+		case GDK_KEY_space: {
+			turbo_down = event->type == GDK_KEY_PRESS;
+			SDL_ClearQueuedAudio(device_id);
+			GB_set_turbo_mode(&gb, turbo_down, turbo_down && rewind_down);
+		break; }
+
+		case GDK_KEY_dead_acute: // fall through
+		case GDK_KEY_acute: // fall through
+		case GDK_KEY_apostrophe:
+			underclock_down = event->type == GDK_KEY_PRESS;
+		break;
+
 		case GDK_KEY_F11: {
 			if (event->type == GDK_KEY_RELEASE) {
 				if (is_fullscreen) {
@@ -869,7 +890,7 @@ static gboolean on_key_press(GtkWidget *w, GdkEventKey *event, gpointer data) {
 					gtk_window_fullscreen(GTK_WINDOW(main_window));
 				}
 			}
-		}
+		break; }
 	}
 	
 	if (event->type == GDK_KEY_PRESS) {
@@ -1405,6 +1426,7 @@ G_MODULE_EXPORT void on_keep_aspect_ratio_changed(GtkWidget *w, gpointer user_da
 G_MODULE_EXPORT void on_rewind_duration_changed(GtkWidget *w, gpointer user_data_gptr) {
 	GtkComboBox *box = GTK_COMBO_BOX(w);
 	config.rewind_duration = g_ascii_strtoll(gtk_combo_box_get_active_id(box), NULL, 10);
+	GB_set_rewind_length(&gb, config.rewind_duration);
 }
 
 G_MODULE_EXPORT void on_sample_rate_changed(GtkWidget *w, gpointer user_data_gptr) {
@@ -1805,6 +1827,17 @@ static void vblank(GB_gameboy_t *gb) {
 	GB_set_pixels_output(gb, get_pixels());
 
 	g_idle_add((GSourceFunc) on_vblank, NULL);
+
+	if (underclock_down && clock_mutliplier > 0.5) {
+		clock_mutliplier -= 1.0/16;
+		GB_set_clock_multiplier(gb, clock_mutliplier);
+	}
+	else if (!underclock_down && clock_mutliplier < 1.0) {
+		clock_mutliplier += 1.0/16;
+		GB_set_clock_multiplier(gb, clock_mutliplier);
+	}
+
+	do_rewind = rewind_down;
 }
 
 static void run(GuiData *gui_data) {
@@ -1985,6 +2018,7 @@ static void start(GuiData *gui_data) {
 	while (running) {
 		if (rewind_paused) {
 			handle_events(&gb);
+			g_usleep(G_USEC_PER_SEC / 8);
 		}
 		else {
 			if (do_rewind) {