diff --git a/exp_scenario/module/commands/waterfill.lua b/exp_scenario/module/commands/waterfill.lua
index 6d9cc9d2..a9313f92 100644
--- a/exp_scenario/module/commands/waterfill.lua
+++ b/exp_scenario/module/commands/waterfill.lua
@@ -70,7 +70,7 @@ SelectArea:on_selection(function(event)
     if #chests > 0 then
         for _, chest in pairs(chests) do
             tile_count = tile_count + 1
-            if chest.get_inventory(defines.inventory.chest).is_empty() and tile_count <= item_count_total then
+            if assert(chest.get_inventory(defines.inventory.chest)).is_empty() and tile_count <= item_count_total then
                 tiles_to_make[tile_count] = { name = tile_to_apply, position = { chest.position.x, chest.position.y } }
                 chest.destroy()
             else
diff --git a/exp_scenario/module/control/custom_start.lua b/exp_scenario/module/control/custom_start.lua
index 1c4e64ff..62d59a1a 100644
--- a/exp_scenario/module/control/custom_start.lua
+++ b/exp_scenario/module/control/custom_start.lua
@@ -8,7 +8,7 @@ local floor = math.floor
 --- Give a player their starting items
 --- @param player LuaPlayer
 local function give_starting_items(player)
-    local get_prod_stats = player.force.get_item_production_statistics(player.physical_surface)
+    local get_prod_stats = (player.force --[[@as LuaForce]]).get_item_production_statistics(player.physical_surface)
     local get_input_count = get_prod_stats.get_input_count
     local insert_param = { name = "", count = 0 }
     local insert = player.insert
diff --git a/exp_scenario/module/control/damage_popups.lua b/exp_scenario/module/control/damage_popups.lua
index 54dfc0e1..146a94fe 100644
--- a/exp_scenario/module/control/damage_popups.lua
+++ b/exp_scenario/module/control/damage_popups.lua
@@ -26,11 +26,12 @@ local function on_entity_damaged(event)
 
     -- Outputs the message as floating text
     if message then
+        local entity_position = entity.position --[[@as MapPosition.struct]]
         local entity_radius = max(1, entity.get_radius())
         local offset = (random() - 0.5) * entity_radius * config.damage_location_variance
-        local position = { x = entity.position.x + offset, y = entity.position.y - entity_radius }
+        local position = { x = entity_position.x + offset, y = entity_position.y - entity_radius }
 
-        local health_percentage = entity.get_health_ratio()
+        local health_percentage = assert(entity.get_health_ratio())
         local color = { r = 1 - health_percentage, g = health_percentage, b = 0 }
 
         FlyingText.create{
diff --git a/exp_scenario/module/control/deconstruction_log.lua b/exp_scenario/module/control/deconstruction_log.lua
index 98ceb9ea..5d1743be 100644
--- a/exp_scenario/module/control/deconstruction_log.lua
+++ b/exp_scenario/module/control/deconstruction_log.lua
@@ -42,7 +42,7 @@ local function format_position(pos)
 end
 
 --- Convert an area to a string
---- @param area BoundingBox
+--- @param area ExpUtil_AABB.Box
 --- @return string
 local function format_area(area)
     return format_string("%.1f,%.1f,%.1f,%.1f", area.left_top.x, area.left_top.y, area.right_bottom.x, area.right_bottom.y)
diff --git a/exp_scenario/module/control/extra_logging.lua b/exp_scenario/module/control/extra_logging.lua
index d469c390..07055245 100644
--- a/exp_scenario/module/control/extra_logging.lua
+++ b/exp_scenario/module/control/extra_logging.lua
@@ -23,7 +23,7 @@ end
 --- @param event EventData.on_cargo_pod_finished_ascending
 local function on_cargo_pod_finished_ascending(event)
     if event.launched_by_rocket then
-        local force = event.cargo_pod.force
+        local force = event.cargo_pod.force --[[@as LuaForce]]
         if force.rockets_launched >= config.rocket_launch_display_rate and force.rockets_launched % config.rocket_launch_display_rate == 0 then
             add_log_line("[ROCKET]", force.rockets_launched, "rockets launched")
         elseif config.rocket_launch_display[force.rockets_launched] then
@@ -38,7 +38,7 @@ local function on_pre_player_died(event)
     local cause = event.cause
     if cause then
         if cause.type == "character" then
-            add_log_line("[DEATH]", player.name, "died because of", cause.player.name)
+            add_log_line("[DEATH]", player.name, "died because of", assert(cause.player).name)
         else
             add_log_line("[DEATH]", player.name, "died because of", cause.name)
         end
diff --git a/exp_util/module/selection.lua b/exp_util/module/selection.lua
index c6695ca7..461963f6 100644
--- a/exp_util/module/selection.lua
+++ b/exp_util/module/selection.lua
@@ -54,7 +54,7 @@ local selection_tool = { name = "selection-tool" }
 --- @param player LuaPlayer
 --- @return boolean?
 local function has_selection_tool_in_hand(player)
-    return player.cursor_stack and player.cursor_stack.valid_for_read and player.cursor_stack.name == "selection-tool"
+    return assert(player.cursor_stack) and assert(player.cursor_stack).valid_for_read and assert(player.cursor_stack).name == "selection-tool"
 end
 
 --- Give a selection tool to a player if they don't have one
@@ -62,7 +62,7 @@ end
 local function give_selection_tool(player)
     if has_selection_tool_in_hand(player) then return end
     player.clear_cursor()
-    player.cursor_stack.set_stack(selection_tool)
+    assert(player.cursor_stack).set_stack(selection_tool)
 
     -- This does not work for selection planners, will make a feature request for it
     --player.cursor_stack_temporary = true
@@ -84,7 +84,7 @@ end
 local function remove_selection_tool(player, old_character)
     -- Remove the selection tool
     if has_selection_tool_in_hand(player) then
-        player.cursor_stack.clear()
+        assert(player.cursor_stack).clear()
     else
         player.remove_item(selection_tool)
     end