diff --git a/scada-common/util.lua b/scada-common/util.lua
index 6176b63..2ae76a7 100644
--- a/scada-common/util.lua
+++ b/scada-common/util.lua
@@ -138,7 +138,7 @@ function util.strminw(str, width) return cc_strings.ensure_width(str, width) end
 
 -- concatenation with built-in to string
 ---@nodiscard
----@vararg any
+---@param ... any
 ---@return string
 function util.concat(...)
     local args, strings = t_pack(...), {}
@@ -152,7 +152,7 @@ util.c = util.concat
 -- sprintf implementation
 ---@nodiscard
 ---@param format string
----@vararg any
+---@param ... any
 function util.sprintf(format, ...) return string.format(format, ...) end
 
 -- format a number string with commas as the thousands separator<br>
diff --git a/supervisor/configure.lua b/supervisor/configure.lua
index a903cbe..0ca7c39 100644
--- a/supervisor/configure.lua
+++ b/supervisor/configure.lua
@@ -295,8 +295,12 @@ local function config_view(display)
             for i = 1, tmp_cfg.UnitCount do
                 local conf = tool_ctl.cooling_elems[i]
                 -- already verified fields are numbers
----@diagnostic disable-next-line: assign-type-mismatch
-                tmp_cfg.CoolingConfig[i] = { TurbineCount = tonumber(conf.turbines.get_value()), BoilerCount = tonumber(conf.boilers.get_value()), TankConnection = conf.tank.get_value() }
+                tmp_cfg.CoolingConfig[i] = {
+                    TurbineCount = tonumber(conf.turbines.get_value()) --[[@as number]],
+                    BoilerCount = tonumber(conf.boilers.get_value()) --[[@as number]],
+                    TankConnection = conf.tank.get_value()
+                }
+
                 if conf.tank.get_value() then any_has_tank = true end
             end
 
diff --git a/supervisor/session/rsctl.lua b/supervisor/session/rsctl.lua
index 5985c9d..b270267 100644
--- a/supervisor/session/rsctl.lua
+++ b/supervisor/session/rsctl.lua
@@ -41,9 +41,7 @@ function rsctl.new(redstone_rtus)
     function public.digital_read(port)
         for i = 1, #redstone_rtus do
             local io = redstone_rtus[i].get_db().io[port]
-            -- this would only be digital, so it would only return boolean or nil
----@diagnostic disable-next-line: return-type-mismatch
-            if io ~= nil then return io.read() end
+            if io ~= nil then return io.read() --[[@as boolean|nil]] end
         end
     end