diff --git a/maps/crab_defender/main.lua b/maps/crab_defender/main.lua
index c9c48855..21ac04ef 100644
--- a/maps/crab_defender/main.lua
+++ b/maps/crab_defender/main.lua
@@ -1125,20 +1125,20 @@ local function deny_building(event)
     return false
 end
 
-local on_built_entity = function(event)
+local on_built_entity = function (event)
     local get_score = Score.get_table().score_table
     local this = FDT.get()
     local entity = event.created_entity
+
+    if not entity or not entity.valid then
+        return
+    end
     local surface = entity.surface
 
     if not surface or not surface.valid then
         return
     end
 
-    if not entity.valid then
-        return
-    end
-
     if deny_building(event) then
         return
     end