--- alexandria-book-collection-manager-0.7.6/lib/alexandria/preferences.rb.negative	2020-11-03 00:35:57.573343839 +0900
+++ alexandria-book-collection-manager-0.7.6/lib/alexandria/preferences.rb	2020-11-03 00:37:21.996312604 +0900
@@ -242,7 +242,7 @@ module Alexandria
         true
       when "false"    # bool
         false
-      when /^[0-9]+$/ # int
+      when /^-?[0-9]+$/ # int
         value.to_i
       when /^\[(.*)\]$/ # list (assume of type String)
         Regexp.last_match[1].split(",")