diff --git a/util/lua-ext.lua b/util/lua-ext.lua
index d0f6f80c..bb320aef 100644
--- a/util/lua-ext.lua
+++ b/util/lua-ext.lua
@@ -57,10 +57,3 @@ function rep(args)
     return str
 end
 
-function table_keys(t)
-    local result = {}
-    for k, v in pairs(t) do
-        table.insert(result, k)
-    end
-    return result
-end