diff --git a/slack-pixiv/commands/pixiv.rb b/slack-pixiv/commands/pixiv.rb
index f449c60..29e47ae 100644
--- a/slack-pixiv/commands/pixiv.rb
+++ b/slack-pixiv/commands/pixiv.rb
@@ -15,7 +15,7 @@ module SlackMathbot
         # ios_url = "pixiv://illusts/" + pixiv_url.split("illust_id=")[-1]
 	illust_url = pixiv_url.split("illust_id=")[-1]
 	puts illust_url
-	ios_url = "pixiv://illusts/" + illust_url.slice(^[0-9]+$)
+	ios_url = "pixiv://illusts/" + illust_url.slice(/^[0-9]+$/)
        	puts ios_url
 
 	# TODO: Create iOS Member URL, must find correct URL scheme