diff --git a/data/scripts/lib/register_achievements.lua b/data/scripts/lib/register_achievements.lua
index 73fd63206af..df3dbff05d6 100644
--- a/data/scripts/lib/register_achievements.lua
+++ b/data/scripts/lib/register_achievements.lua
@@ -642,7 +642,8 @@ function Player.addAchievementProgress(self, achievement, totalProgress)
 	end
 
 	local progressNumber = self:getStorageValue(storage)
-	local progressNumber self:kv():scoped("achievements"):get("progress")
+	local progressNumber
+	self:kv():scoped("achievements"):get("progress")
 	if progressNumber and progressNumber <= totalProgress then
 		if progressNumber == totalProgress then
 			self:addAchievement(foundAchievement.id)