diff --git a/parts/scenes/custom_field.lua b/parts/scenes/custom_field.lua
index ac7bc33b..5c43db49 100644
--- a/parts/scenes/custom_field.lua
+++ b/parts/scenes/custom_field.lua
@@ -195,7 +195,7 @@ function scene.keyDown(key)
         local F=FIELD[page]
         local cleared=false
         for i=#F,1,-1 do
-            local full
+            local full=true
             for j=1,10 do
                 if F[i][j]<=0 then full=false break end-- goto CONTINUE_notFull
             end