diff --git a/lib/kafkaex_lag_exporter/consumer_offset_fetcher.ex b/lib/kafkaex_lag_exporter/consumer_offset_fetcher.ex
index 38abeb8..1435d20 100644
--- a/lib/kafkaex_lag_exporter/consumer_offset_fetcher.ex
+++ b/lib/kafkaex_lag_exporter/consumer_offset_fetcher.ex
@@ -4,10 +4,9 @@ defmodule KafkaexLagExporter.ConsumerOffsetFetcher do
   alias KafkaexLagExporter.ConsumerOffset
   alias KafkaexLagExporter.KafkaUtils
 
-  # TODO fix type
   @spec get(KafkaexLagExporter.KafkaWrapper.Behaviour.endpoint()) :: %{
-          lags: list(binary),
-          sum: list(binary)
+          lags: list(ConsumerOffset.t()),
+          sum: list(ConsumerOffset.t())
         }
   def get(endpoint) do
     consumer_group_names = KafkaUtils.get_consumer_group_names(endpoint)
diff --git a/lib/kafkaex_lag_exporter/consumer_offset_runner.ex b/lib/kafkaex_lag_exporter/consumer_offset_runner.ex
index 591c1d4..41e2ea1 100644
--- a/lib/kafkaex_lag_exporter/consumer_offset_runner.ex
+++ b/lib/kafkaex_lag_exporter/consumer_offset_runner.ex
@@ -29,7 +29,7 @@ defmodule KafkaexLagExporter.ConsumerOffsetRunner do
   def handle_info(:tick, state) do
     [endpoint | _] = state.endpoints
 
-    %{sum: lag_sum, lags: lags} = KafkaexLagExporter.ConsumerOffsetFetcher.get(endpoint)
+    %{lags: lags, sum: lag_sum} = KafkaexLagExporter.ConsumerOffsetFetcher.get(endpoint)
 
     KafkaexLagExporter.Metrics.group_lag_per_partition(endpoint, lags)
     KafkaexLagExporter.Metrics.group_sum_lag(endpoint, lag_sum)
diff --git a/lib/kafkaex_lag_exporter/metrics.ex b/lib/kafkaex_lag_exporter/metrics.ex
index 3e2129f..6118410 100644
--- a/lib/kafkaex_lag_exporter/metrics.ex
+++ b/lib/kafkaex_lag_exporter/metrics.ex
@@ -36,9 +36,13 @@ defmodule KafkaexLagExporter.Metrics do
     )
   end
 
+  @spec group_sum_lag(
+          KafkaexLagExporter.KafkaWrapper.Behaviour.endpoint(),
+          list(ConsumerOffset.t())
+        ) :: :ok
   @doc false
-  def group_sum_lag({host, _port}, cunsumer_offsets) do
-    Enum.each(cunsumer_offsets, fn %ConsumerOffset{} = consumer_offset ->
+  def group_sum_lag({host, _port}, consumer_offsets) do
+    Enum.each(consumer_offsets, fn %ConsumerOffset{} = consumer_offset ->
       lag = elem(consumer_offset.lag, 1)
 
       :telemetry.execute(
@@ -55,6 +59,10 @@ defmodule KafkaexLagExporter.Metrics do
     end)
   end
 
+  @spec group_lag_per_partition(
+          KafkaexLagExporter.KafkaWrapper.Behaviour.endpoint(),
+          list(ConsumerOffset.t())
+        ) :: :ok
   @doc false
   def group_lag_per_partition({host, _port}, consumer_offsets) do
     Enum.each(consumer_offsets, fn %ConsumerOffset{} = consumer_offset ->