diff --git a/docs/how_to_make_dicebot.md b/docs/how_to_make_dicebot.md
index 803b75c52..c7cfab9fb 100644
--- a/docs/how_to_make_dicebot.md
+++ b/docs/how_to_make_dicebot.md
@@ -307,7 +307,7 @@ BCDiceは入力された文字列にたいして様々な前処理を行った
       private
 
       def roll_ot(command)
-        m = /^(\d)+OT>=(\d+)$/.match(command)
+        m = /^(\d+)OT>=(\d+)$/.match(command)
         return nil unless m
 
         times = m[1].to_i
diff --git a/example/OnseTool.rb b/example/OnseTool.rb
index 208cb04b1..4185ee1a7 100644
--- a/example/OnseTool.rb
+++ b/example/OnseTool.rb
@@ -45,7 +45,7 @@ def eval_game_system_specific_command(command)
       private
 
       def roll_ot(command)
-        m = /^(\d)+OT>=(\d+)$/.match(command)
+        m = /^(\d+)OT>=(\d+)$/.match(command)
         return nil unless m
 
         times = m[1].to_i