diff --git a/core/cache.lua b/core/cache.lua
index 596b26d..c4e0b76 100644
--- a/core/cache.lua
+++ b/core/cache.lua
@@ -46,7 +46,7 @@ do
 	end
 	function LOAD2()
 		characters = realm_data'characters'
-		for k, v in characters do
+		for k, v in pairs(characters) do
 			if GetTime() > v + 60 * 60 * 24 * 30 then
 				characters[k] = nil
 			end
diff --git a/core/disenchant.lua b/core/disenchant.lua
index 7536512..466cd12 100644
--- a/core/disenchant.lua
+++ b/core/disenchant.lua
@@ -37,7 +37,7 @@ local WEAPON = S(
 
 function M.value(slot, quality, level)
     local expectation
-    for _, event in distribution(slot, quality, level) do
+    for _, event in pairs(distribution(slot, quality, level)) do
         local value = history.value(event.item_id .. ':' .. 0)
         if not value then
             return
diff --git a/core/history.lua b/core/history.lua
index c7ed1d6..c130838 100644
--- a/core/history.lua
+++ b/core/history.lua
@@ -65,12 +65,12 @@ function M.value(item_key)
 		item_record = read_record(item_key)
 		if getn(item_record.data_points) > 0 then
 			local total_weight, weighted_values = 0, temp-T
-			for _, data_point in item_record.data_points do
+			for _, data_point in pairs(item_record.data_points) do
 				local weight = .99 ^ round((item_record.data_points[1].time - data_point.time) / (60 * 60 * 24))
 				total_weight = total_weight + weight
 				tinsert(weighted_values, O('value', data_point.value, 'weight', weight))
 			end
-			for _, weighted_value in weighted_values do
+			for _, weighted_value in pairs(weighted_values) do
 				weighted_value.weight = weighted_value.weight / total_weight
 			end
 			value = weighted_median(weighted_values)
@@ -89,10 +89,10 @@ end
 function weighted_median(list)
 	sort(list, function(a,b) return a.value < b.value end)
 	local weight = 0
-	for i = 1, getn(list) do
-		weight = weight + list[i].weight
+	for _, v in ipairs(list) do
+		weight = weight + v.weight
 		if weight >= .5 then
-			return list[i].value
+			return v.value
 		end
 	end
 end
diff --git a/core/scan.lua b/core/scan.lua
index 68d265f..41d85cc 100644
--- a/core/scan.lua
+++ b/core/scan.lua
@@ -27,14 +27,14 @@ do
 
 	function M.abort(scan_id)
 		local aborted = T
-		for type, state in scan_states do
+		for type, state in pairs(scan_states) do
 			if not scan_id or state.id == scan_id then
 				kill_thread(state.id)
 				scan_states[type] = nil
 				tinsert(aborted, state)
 			end
 		end
-		for _, state in aborted do
+		for _, state in pairs(aborted) do
 			do (state.params.on_abort or nop)() end
 		end
 	end
@@ -50,7 +50,7 @@ do
 	end
 
 	function get_state()
-		for _, state in scan_states do
+		for _, state in pairs(scan_states) do
 			if state.id == thread_id then
 				return state
 			end
diff --git a/core/tooltip.lua b/core/tooltip.lua
index 6534757..fcbd6f9 100644
--- a/core/tooltip.lua
+++ b/core/tooltip.lua
@@ -18,7 +18,7 @@ function LOAD()
 	settings = character_data('tooltip', {value=true})
 	do
 		local inside_hook = false
-	    for name, f in game_tooltip_hooks do
+	    for name, f in pairs(game_tooltip_hooks) do
 	        local name, f = name, f
 	        hook(name, GameTooltip, vararg-function(arg)
 	            inside_hook = true
@@ -61,8 +61,7 @@ function M.extend_tooltip(tooltip, link, quantity)
             if settings.disenchant_distribution then
                 tooltip:AddLine('Disenchants into:', color.tooltip.disenchant.distribution())
                 sort(distribution, function(a,b) return a.probability > b.probability end)
-                for i = 1, getn(distribution) do
-	                local event = distribution[i]
+                for _, event in ipairs(distribution) do
                     tooltip:AddLine(format('  %s%% %s (%s-%s)', event.probability * 100, info.display_name(event.item_id, true) or 'item:' .. event.item_id, event.min_quantity, event.max_quantity), color.tooltip.disenchant.distribution())
                 end
             end
diff --git a/util.lua b/util.lua
index 31ae73b..c30d9ea 100644
--- a/util.lua
+++ b/util.lua
@@ -32,7 +32,10 @@ end
 
 M.index = vararg-function(arg)
 	local t = tremove(arg, 1)
-	for i = 1, getn(arg) do t = t and t[arg[i]] end return t
+	for _, v in ipairs(arg) do
+		t = t and t[v]
+	end
+	return t
 end
 
 M.huge = 1.8 * 10 ^ 308
@@ -43,46 +46,58 @@ end
 
 function M.copy(t)
 	local copy = T
-	for k, v in t do copy[k] = v end
+	for k, v in pairs(t) do
+		copy[k] = v
+	end
 	table.setn(copy, getn(t))
 	return setmetatable(copy, getmetatable(t))
 end
 
 function M.size(t)
 	local size = 0
-	for _ in t do size = size + 1 end
+	for _ in pairs(t) do
+		size = size + 1
+	end
 	return size
 end
 
 function M.key(t, value)
-	for k, v in t do if v == value then return k end end
+	for k, v in pairs(t) do
+		if v == value then
+			return k
+		end
+	end
 end
 
 function M.keys(t)
 	local keys = T
-	for k in t do tinsert(keys, k) end
+	for k in pairs(t) do
+		tinsert(keys, k)
+	end
 	return keys
 end
 
 function M.values(t)
 	local values = T
-	for _, v in t do tinsert(values, v) end
+	for _, v in pairs(t) do
+		tinsert(values, v)
+	end
 	return values
 end
 
 function M.eq(t1, t2)
 	if not t1 or not t2 then return false end
-	for key, value in t1 do
+	for key, value in pairs(t1) do
 		if t2[key] ~= value then return false end
 	end
-	for key, value in t2 do
+	for key, value in pairs(t2) do
 		if t1[key] ~= value then return false end
 	end
 	return true
 end
 
 function M.any(t, predicate)
-	for _, v in t do
+	for _, v in pairs(t) do
 		if predicate then
 			if predicate(v) then return true end
 		elseif v then
@@ -93,7 +108,7 @@ function M.any(t, predicate)
 end
 
 function M.all(t, predicate)
-	for _, v in t do
+	for _, v in pairs(t) do
 		if predicate then
 			if not predicate(v) then return false end
 		elseif not v then
@@ -104,14 +119,16 @@ function M.all(t, predicate)
 end
 
 function M.filter(t, predicate)
-	for k, v in t do
+	for k, v in pairs(t) do
 		if not predicate(v, k) then t[k] = nil end
 	end
 	return t
 end
 
 function M.map(t, f)
-	for k, v in t do t[k] = f(v, k) end
+	for k, v in pairs(t) do
+		t[k] = f(v, k)
+	end
 	return t
 end