diff --git a/angelsrefining/changelog.txt b/angelsrefining/changelog.txt
index 5b8bd96cf..7100403a9 100644
--- a/angelsrefining/changelog.txt
+++ b/angelsrefining/changelog.txt
@@ -3,6 +3,7 @@ Version: 0.12.8
 Date: ???
   Bugfixes:
     - Fixed when placing an electric offshore waterpump over its ghost, the module request would be forgotten (973)
+    - Fixed crash when upgrading blueprints (978)
   Changes:
     - Added Ore Sorting Facility 5. Catalyst sorting requires a higher tier ore sorting facility (979)
 ---------------------------------------------------------------------------------------------------
diff --git a/angelsrefining/src/sea-pump.lua b/angelsrefining/src/sea-pump.lua
index f54b2ac9b..419b9c348 100644
--- a/angelsrefining/src/sea-pump.lua
+++ b/angelsrefining/src/sea-pump.lua
@@ -203,6 +203,11 @@ function sea_pump:on_blueprint_setup(player_index)
     end
   end
 
+  -- type may be 'upgrade-item'
+  if blueprint.type ~= 'blueprint' then
+    return
+  end
+
   -- obtain all blueprint entitites
   local entities = blueprint.get_blueprint_entities()
   if entities == nil then