--- widgets/misc/e-calendar-item.c
+++ widgets/misc/e-calendar-item.c
@@ -434,10 +434,10 @@
 		calitem->styles = NULL;
 	}
 
-	if (calitem->signal_emission_idle_id != 0) {
+	if (calitem->signal_emission_idle_id > 0) {
 		g_source_remove (calitem->signal_emission_idle_id);
-		calitem->signal_emission_idle_id = 0;
+		calitem->signal_emission_idle_id = -1;
 	}
 
 	if (calitem->font_desc) {

--- calendar/gui/dialogs/recurrence-page.c
+++ calendar/gui/dialogs/recurrence-page.c
@@ -846,7 +849,7 @@
 	/* If our component has not been set yet through ::fill_widgets(), we
 	 * cannot preview the recurrence.
 	 */
-	if (!priv->comp || e_cal_component_is_instance (priv->comp))
+	if (!priv || !priv->comp || e_cal_component_is_instance (priv->comp))
 		return;
 
 	/* Create a scratch component with the start/end and