diff --git a/api/api.lua b/api/api.lua
index d5cb942a..076a8e79 100644
--- a/api/api.lua
+++ b/api/api.lua
@@ -27,10 +27,8 @@ function pfUI.api.UnitInRange(unit)
     return nil
   elseif CheckInteractDistance(unit, 4) then
     return 1
-  elseif pfUI.rangecheck then
-    return pfUI.rangecheck:UnitInSpellRange(unit)
   else
-    return nil
+    return librange:UnitInSpellRange(unit)
   end
 end
 
diff --git a/libs/librange.lua b/libs/librange.lua
new file mode 100644
index 00000000..0817da7e
--- /dev/null
+++ b/libs/librange.lua
@@ -0,0 +1,186 @@
+-- load pfUI environment
+setfenv(1, pfUI:GetEnvironment())
+
+--[[ librange ]]--
+-- A pfUI library that detects and caches distance to units.
+--
+--  librange:UnitInSpellRange(unit)
+--    Returns `1` if the unit is within a 40y range
+--
+
+local librange = CreateFrame("Frame", "pfRangecheck", UIParent)
+
+-- table of 40y spells per class
+local spells = {
+  ["PALADIN"] = {
+    "Interface\\Icons\\Spell_Holy_FlashHeal",
+    "Interface\\Icons\\Spell_Holy_HolyBolt",
+  },
+  ["PRIEST"] = {
+    "Interface\\Icons\\Spell_Holy_FlashHeal",
+    "Interface\\Icons\\Spell_Holy_LesserHeal",
+    "Interface\\Icons\\Spell_Holy_Heal",
+    "Interface\\Icons\\Spell_Holy_GreaterHeal",
+    "Interface\\Icons\\Spell_Holy_Renew",
+  },
+  ["DRUID"] = {
+    "Interface\\Icons\\Spell_Nature_HealingTouch",
+    "Interface\\Icons\\Spell_Nature_ResistNature",
+    "Interface\\Icons\\Spell_Nature_Rejuvenation",
+  },
+  ["SHAMAN"] = {
+    "Interface\\Icons\\Spell_Nature_MagicImmunity",
+    "Interface\\Icons\\Spell_Nature_HealingWaveLesser",
+    "Interface\\Icons\\Spell_Nature_HealingWaveGreater",
+  },
+}
+
+-- units that should be scanned
+local units = {}
+table.insert(units, "pet")
+for i=1,4 do table.insert(units, "party" .. i) end
+for i=1,4 do table.insert(units, "partypet" .. i) end
+for i=1,40 do table.insert(units, "raid" .. i) end
+for i=1,40 do table.insert(units, "raidpet" .. i) end
+local numunits = table.getn(units)
+
+-- cache for unit relations
+local unitcache = {}
+
+-- actual unit-range table
+local unitdata = { }
+
+librange.id = 1
+
+librange:Hide()
+librange:RegisterEvent("ACTIONBAR_SLOT_CHANGED")
+librange:RegisterEvent("PLAYER_ENTERING_WORLD")
+librange:RegisterEvent("PLAYER_ENTER_COMBAT")
+librange:RegisterEvent("PLAYER_LEAVE_COMBAT")
+librange:SetScript("OnEvent", function()
+  local _, class = UnitClass("player")
+
+  -- disable range checking activities
+  if C.unitframes.rangecheck == "0" or not spells[class] then
+    this:Hide()
+    return
+  end
+
+  this.interval = tonumber(C.unitframes.rangechecki)/numunits
+
+  if event == "ACTIONBAR_SLOT_CHANGED" or event == "PLAYER_ENTERING_WORLD" then
+    librange.slot = this:GetRangeSlot()
+  elseif event == "PLAYER_ENTER_COMBAT" then
+    this.lastattack = GetTime()
+    this:Hide()
+  elseif event == "PLAYER_LEAVE_COMBAT" then
+    if not this:ReAttack() then
+      this:Show()
+    end
+  end
+end)
+
+librange:SetScript("OnUpdate", function()
+  if ( this.tick or 1) > GetTime() then
+    return
+  else
+    this.tick = GetTime() + this.interval
+  end
+
+  -- skip invalid units
+  while not this:NeedRangeScan(units[this.id]) and this.id <= numunits do
+    this.id = this.id + 1
+  end
+
+  if this.id <= numunits and librange.slot then
+    local unit = units[this.id]
+    if not UnitIsUnit("target", unit) then
+      -- suspend for various conditions
+      if pfUI.loot and pfUI.loot:IsShown() then return nil end
+      if LootFrame and LootFrame:IsShown() then return nil end
+      if InspectFrame and InspectFrame:IsShown() then return nil end
+      if TradeFrame and TradeFrame:IsShown() then return nil end
+
+      pfScanActive = true
+      TargetUnit(unit)
+      unitdata[unit] = IsActionInRange(librange.slot)
+      TargetLastTarget()
+      pfScanActive = false
+      this:ReAttack()
+    end
+
+    this.id = this.id + 1
+  else
+    this.id = 1
+  end
+end)
+
+function librange:ReAttack()
+  -- we accidentally broke the autoattack... restoring the old state
+  if this.lastattack and this.lastattack + this.interval > GetTime() and UnitCanAttack("player", "target") then
+    AttackTarget()
+    return true
+  else
+    return nil
+  end
+end
+
+function librange:NeedRangeScan(unit)
+  if not UnitExists(unit) then return nil end
+  if not UnitIsVisible(unit) then return nil end
+  if CheckInteractDistance(unit, 4) then return nil end
+  return true
+end
+
+function librange:GetRealUnit(unit)
+  if unitdata[unit] then return unit end
+
+  if unitcache[unit] then
+    if UnitIsUnit(unitcache[unit], unit) then
+      return unitcache[unit]
+    end
+  end
+
+  for id, realunit in pairs(units) do
+    if UnitIsUnit(realunit, unit) then
+      unitcache[unit] = realunit
+      return realunit
+    end
+  end
+
+  return unit
+end
+
+function librange:GetRangeSlot()
+  for i=1,120 do
+    local texture = GetActionTexture(i)
+    for _, check in pairs(spells[class]) do
+      if check == texture then
+        return i
+      end
+    end
+  end
+
+  return nil
+end
+
+function librange:UnitInSpellRange(unit)
+  if not librange.slot then return nil end
+
+  if UnitIsUnit("target", unit) then
+    return IsActionInRange(librange.slot) == 1 and 1 or nil
+  end
+
+  local unit = librange:GetRealUnit(unit)
+
+  if unitdata[unit] and unitdata[unit] == 1 then
+    return 1
+  elseif not unitdata[unit] then
+    return 1
+  else
+    return nil
+  end
+end
+
+-- add libdebuff to pfUI API
+pfUI.api.librange = librange
diff --git a/modules/rangecheck.lua b/modules/rangecheck.lua
index 5f0d8860..e69de29b 100644
--- a/modules/rangecheck.lua
+++ b/modules/rangecheck.lua
@@ -1,171 +0,0 @@
-pfUI:RegisterModule("rangecheck", function ()
-
-  if C.unitframes.rangecheck == "0" then return end
-
-  -- table of 40y spells per class
-  local spells = {
-    ["PALADIN"] = {
-      "Interface\\Icons\\Spell_Holy_FlashHeal",
-      "Interface\\Icons\\Spell_Holy_HolyBolt",
-    },
-    ["PRIEST"] = {
-      "Interface\\Icons\\Spell_Holy_FlashHeal",
-      "Interface\\Icons\\Spell_Holy_LesserHeal",
-      "Interface\\Icons\\Spell_Holy_Heal",
-      "Interface\\Icons\\Spell_Holy_GreaterHeal",
-      "Interface\\Icons\\Spell_Holy_Renew",
-    },
-    ["DRUID"] = {
-      "Interface\\Icons\\Spell_Nature_HealingTouch",
-      "Interface\\Icons\\Spell_Nature_ResistNature",
-      "Interface\\Icons\\Spell_Nature_Rejuvenation",
-    },
-    ["SHAMAN"] = {
-      "Interface\\Icons\\Spell_Nature_MagicImmunity",
-      "Interface\\Icons\\Spell_Nature_HealingWaveLesser",
-      "Interface\\Icons\\Spell_Nature_HealingWaveGreater",
-    },
-  }
-
-  local _, class = UnitClass("player")
-  if not spells[class] then return end
-
-  -- units that should be scanned
-  local units = {}
-  table.insert(units, "pet")
-  for i=1,4 do table.insert(units, "party" .. i) end
-  for i=1,4 do table.insert(units, "partypet" .. i) end
-  for i=1,40 do table.insert(units, "raid" .. i) end
-  for i=1,40 do table.insert(units, "raidpet" .. i) end
-  local numunits = table.getn(units)
-
-  -- cache for unit relations
-  local unitcache = {}
-
-  -- actual unit-range table
-  local unitdata = { }
-
-  -- the interval between each range check
-  local interval = tonumber(C.unitframes.rangechecki)/numunits
-
-  pfUI.rangecheck = CreateFrame("Frame", "pfRangecheck", UIParent)
-  pfUI.rangecheck.id = 1
-  pfUI.rangecheck:RegisterEvent("ACTIONBAR_SLOT_CHANGED")
-  pfUI.rangecheck:RegisterEvent("PLAYER_ENTERING_WORLD")
-  pfUI.rangecheck:RegisterEvent("PLAYER_ENTER_COMBAT")
-  pfUI.rangecheck:RegisterEvent("PLAYER_LEAVE_COMBAT")
-  pfUI.rangecheck:SetScript("OnEvent", function()
-    if event == "ACTIONBAR_SLOT_CHANGED" or event == "PLAYER_ENTERING_WORLD" then
-      pfUI.rangecheck.slot = this:GetRangeSlot()
-    elseif event == "PLAYER_ENTER_COMBAT" then
-      this.lastattack = GetTime()
-      this:Hide()
-    elseif event == "PLAYER_LEAVE_COMBAT" then
-      if not this:ReAttack() then
-        this:Show()
-      end
-    end
-  end)
-
-  pfUI.rangecheck:SetScript("OnUpdate", function()
-    if ( this.tick or 1) > GetTime() then
-      return
-    else
-      this.tick = GetTime() + interval
-    end
-
-    -- skip invalid units
-    while not this:NeedRangeScan(units[this.id]) and this.id <= numunits do
-      this.id = this.id + 1
-    end
-
-    if this.id <= numunits and pfUI.rangecheck.slot then
-      local unit = units[this.id]
-      if not UnitIsUnit("target", unit) then
-        -- suspend for various conditions
-        if pfUI.loot and pfUI.loot:IsShown() then return nil end
-        if LootFrame and LootFrame:IsShown() then return nil end
-        if InspectFrame and InspectFrame:IsShown() then return nil end
-        if TradeFrame and TradeFrame:IsShown() then return nil end
-
-        pfScanActive = true
-        TargetUnit(unit)
-        unitdata[unit] = IsActionInRange(pfUI.rangecheck.slot)
-        TargetLastTarget()
-        pfScanActive = false
-        this:ReAttack()
-      end
-
-      this.id = this.id + 1
-    else
-      this.id = 1
-    end
-  end)
-
-  function pfUI.rangecheck:ReAttack()
-    -- we accidentally broke the autoattack... restoring the old state
-    if this.lastattack and this.lastattack + interval > GetTime() and UnitCanAttack("player", "target") then
-      AttackTarget()
-      return true
-    else
-      return nil
-    end
-  end
-
-  function pfUI.rangecheck:NeedRangeScan(unit)
-    if not UnitExists(unit) then return nil end
-    if not UnitIsVisible(unit) then return nil end
-    if CheckInteractDistance(unit, 4) then return nil end
-    return true
-  end
-
-  function pfUI.rangecheck:GetRealUnit(unit)
-    if unitdata[unit] then return unit end
-
-    if unitcache[unit] then
-      if UnitIsUnit(unitcache[unit], unit) then
-        return unitcache[unit]
-      end
-    end
-
-    for id, realunit in pairs(units) do
-      if UnitIsUnit(realunit, unit) then
-        unitcache[unit] = realunit
-        return realunit
-      end
-    end
-
-    return unit
-  end
-
-  function pfUI.rangecheck:GetRangeSlot()
-    for i=1,120 do
-      local texture = GetActionTexture(i)
-      for _, check in pairs(spells[class]) do
-        if check == texture then
-          return i
-        end
-      end
-    end
-
-    return nil
-  end
-
-  function pfUI.rangecheck:UnitInSpellRange(unit)
-    if not pfUI.rangecheck.slot then return nil end
-
-    if UnitIsUnit("target", unit) then
-      return IsActionInRange(pfUI.rangecheck.slot) == 1 and 1 or nil
-    end
-
-    local unit = pfUI.rangecheck:GetRealUnit(unit)
-
-    if unitdata[unit] and unitdata[unit] == 1 then
-      return 1
-    elseif not unitdata[unit] then
-      return 1
-    else
-      return nil
-    end
-  end
-end)
diff --git a/pfUI.toc b/pfUI.toc
index eab16bc4..4b0a0b4b 100644
--- a/pfUI.toc
+++ b/pfUI.toc
@@ -42,6 +42,7 @@ api\unitframes.lua
 # libs
 libs\libcast.lua
 libs\libdebuff.lua
+libs\librange.lua
 
 # modules
 modules\firstrun.lua
@@ -51,7 +52,6 @@ modules\hoverbind.lua
 modules\updatenotify.lua
 modules\actionbar.lua
 modules\hunterbar.lua
-modules\rangecheck.lua
 modules\chat.lua
 modules\bubbles.lua
 modules\addons.lua