diff --git a/lib/core/aggregator.ex b/lib/core/aggregator.ex
index 366245a..4b47773 100644
--- a/lib/core/aggregator.ex
+++ b/lib/core/aggregator.ex
@@ -86,6 +86,10 @@ defmodule TelemetryMetricsPrometheus.Core.Aggregator do
   end
 
   @spec get_aggregation(key :: key(), table :: atom()) :: {} | aggregation()
+  defp get_aggregation(key, table) when is_atom(key) do
+    get_aggregation(to_string(key), table)
+  end
+  
   defp get_aggregation(key, table) do
     case :ets.lookup(table, key) do
       [] -> {}
@@ -96,6 +100,10 @@ defmodule TelemetryMetricsPrometheus.Core.Aggregator do
   @spec put_aggregation(aggregation :: nil | aggregation(), key :: key(), table :: atom()) :: true
   def put_aggregation(nil, _, _), do: true
 
+  def put_aggregation(aggregation, key, tid) when is_atom(key) do
+    put_aggregation(aggregation, to_string(key), tid)
+  end
+
   def put_aggregation(aggregation, key, tid) do
     :ets.insert(tid, {key, aggregation})
   end