diff --git a/src/calls-new-call-box.c b/src/calls-new-call-box.c
index c9151a5..2f42be2 100644
--- a/src/calls-new-call-box.c
+++ b/src/calls-new-call-box.c
@@ -65,8 +65,9 @@ dial_pad_symbol_clicked_cb (CallsNewCallBox *self,
 {
   GtkEntryBuffer *buf = gtk_entry_get_buffer (GTK_ENTRY (self->number_entry));
   guint len = gtk_entry_buffer_get_length (buf);
+  const gchar str[] = {symbol, '\0'};
 
-  gtk_entry_buffer_insert_text (buf, len, &symbol, 1);
+  gtk_entry_buffer_insert_text (buf, len, str, 1);
 }