diff --git a/lib/tower_rollbar/rollbar/item.ex b/lib/tower_rollbar/rollbar/item.ex
index 5719cdd..cd909ff 100644
--- a/lib/tower_rollbar/rollbar/item.ex
+++ b/lib/tower_rollbar/rollbar/item.ex
@@ -98,9 +98,25 @@ defmodule TowerRollbar.Rollbar.Item do
     }
   end
 
-  defp frames(_stacktrace) do
-    # TODO: implement
-    []
+  defp frames(stacktrace) do
+    stacktrace
+    |> Enum.map(fn {_m, _f, _a, location} ->
+      frame = %{}
+
+      frame =
+        if location[:file] do
+          Map.put(frame, "filename", to_string(location[:file]))
+        else
+          frame
+        end
+
+      if location[:line] do
+        Map.put(frame, "lineno", location[:line])
+      else
+        frame
+      end
+    end)
+    |> Enum.reverse()
   end
 
   defp environment do
diff --git a/test/tower_rollbar/rollbar/item_test.exs b/test/tower_rollbar/rollbar/item_test.exs
index 6842661..f8fba9f 100644
--- a/test/tower_rollbar/rollbar/item_test.exs
+++ b/test/tower_rollbar/rollbar/item_test.exs
@@ -22,7 +22,24 @@ defmodule TowerRollbar.Rollbar.ItemTest do
                "level" => "error",
                "body" => %{
                  "trace" => %{
-                   "frames" => [],
+                   "frames" => [
+                     %{
+                       "filename" => "lib/ex_unit/runner.ex",
+                       "lineno" => _
+                     },
+                     %{
+                       "filename" => "timer.erl",
+                       "lineno" => _
+                     },
+                     %{
+                       "filename" => "lib/ex_unit/runner.ex",
+                       "lineno" => _
+                     },
+                     %{
+                       "filename" => "test/tower_rollbar/rollbar/item_test.exs",
+                       "lineno" => 12
+                     }
+                   ],
                    "exception" => %{
                      "class" => "RuntimeError",
                      "message" => "a test"