diff --git a/Changes.md b/Changes.md
index 92c91d8..590447f 100644
--- a/Changes.md
+++ b/Changes.md
@@ -19,7 +19,7 @@ Fixed:
 
 - Deprecate the use of `io.popen` in following widgets:
     * wifi_linux, wifiiw_linux, hwmontemp_linux, hddtemp_linux
-    * bat_freebsd, mem_freebsd, net_freebsd
+    * bat_freebsd, mem_freebsd, net_freebsd, thermal_freebsd
     * volume, gmail, mdir, mpd, fs
 - [mpd] Lua 5.3 compatibility (for real this time); also correct a typo
 - [pkg,weather,contrib/btc] Allow function call without Awesome
diff --git a/helpers.lua b/helpers.lua
index 2f56a2b..ed11043 100644
--- a/helpers.lua
+++ b/helpers.lua
@@ -19,10 +19,12 @@ local getmetatable = getmetatable
 local string = {
     upper = string.upper,
     lower = string.lower,
-    format = string.format
+    format = string.format,
+    match = string.match,
 }
 local pcall = pcall
 local assert = assert
+local spawn = require("vicious.spawn")
 -- }}}
 
 
@@ -260,6 +262,21 @@ function helpers.sysctl_table(syspath)
 end
 -- }}}
 
+-- {{{ Return result from sysctl variable as table (async)
+function helpers.sysctl_async(path, parse)
+    local ret = {}
+    local path = table.concat(path, " ")
+
+    spawn.with_line_callback("sysctl " .. helpers.shellquote(path), {
+        stdout = function(line)
+            local key, value = string.match(line, "(.+): (.+)")
+            ret[key] = value
+        end,
+        output_done = function() parse(ret) end
+    })
+end
+--  }}}
+
 return helpers
 
 -- }}}
diff --git a/widgets/thermal_freebsd.lua b/widgets/thermal_freebsd.lua
index 3387a52..5a7dbe7 100644
--- a/widgets/thermal_freebsd.lua
+++ b/widgets/thermal_freebsd.lua
@@ -1,5 +1,4 @@
 -- {{{ Grab environment
-local setmetatable = setmetatable
 local string = { match = string.match }
 local helpers = require("vicious.helpers")
 -- }}}
@@ -9,26 +8,25 @@ local helpers = require("vicious.helpers")
 -- vicious.widgets.thermal
 local thermal_freebsd = {}
 
-
 -- {{{ Thermal widget type
-local function worker(format, warg)
-    if not warg then return end
+function thermal_freebsd.async(format, warg, callback)
+    if not warg then return callback{} end
     if type(warg) ~= "table" then warg = { warg } end
 
     local thermals = {}
 
-    for i=1, #warg do
-        local output = helpers.sysctl(warg[i])
-
-        if not output then
-            thermals[i] = -1
-        else
-            thermals[i] = string.match(output, "[%d]+")
+    helpers.sysctl_async(warg, function(ret)
+        for i=1, #warg do
+            if ret[warg[i]] ~= nil then
+                thermals[i] = string.match(ret[warg[i]], "[%d]+")
+            else
+                thermals[i] = "N/A"
+            end
         end
-    end
 
-    return thermals
+        callback(thermals)
+    end)
 end
 -- }}}
 
-return setmetatable(thermal_freebsd, { __call = function(_, ...) return worker(...) end })
+return helpers.setasyncall(thermal_freebsd)