1 files changed, 1 insertions, 1 deletions
diff --git a/AvailableColumnsPanel.c b/AvailableColumnsPanel.c
index 8aedde24..0d9749e7 100644
--- a/AvailableColumnsPanel.c
+++ b/AvailableColumnsPanel.c
@@ -45,7 +45,7 @@ static HandlerResult AvailableColumnsPanel_eventHandler(Panel* super, int ch) {
       }
       default:
       {
-         if (ch < 255 && isalpha(ch))
+         if (0 < ch && ch < 255 && isalpha((unsigned char)ch))
             result = Panel_selectByTyping(super, ch);
          break;
       }