diff --git a/functional.lua b/functional.lua
index d855a62..b8d9062 100644
--- a/functional.lua
+++ b/functional.lua
@@ -112,20 +112,6 @@ function functional.zip(t1, t2, f)
 	return ret
 end
 
---return a copy of a sequence with all duplicates removed
---	causes a little "extra" gc churn; one table and one closure
---	as well as the copied deduped table
-function functional.dedupe(t)
-	local seen = {}
-	return functional.filter(t, function(v)
-		if seen[v] then
-			return false
-		end
-		seen[v] = true
-		return true
-	end)
-end
-
 -----------------------------------------------------------
 --common queries and reductions
 -----------------------------------------------------------
diff --git a/tablex.lua b/tablex.lua
index 7344168..3027517 100644
--- a/tablex.lua
+++ b/tablex.lua
@@ -146,6 +146,20 @@ function tablex.append(t1, t2)
 	return r
 end
 
+--return a copy of a sequence with all duplicates removed
+--	causes a little "extra" gc churn of one table to track the duplicates internally
+function tablex.dedupe(t)
+	local seen = {}
+	local r = {}
+	for i,v in ipairs(t) do
+		if not seen[v] then
+			seen[v] = true
+			table.insert(r, v)
+		end
+	end
+	return r
+end
+
 --(might already exist depending on luajit)
 if table.clear then
 	--import from global if it exists