diff --git a/lib/ex_parameterized/params.ex b/lib/ex_parameterized/params.ex
index 0a2a608..12857f7 100644
--- a/lib/ex_parameterized/params.ex
+++ b/lib/ex_parameterized/params.ex
@@ -89,7 +89,7 @@ defmodule ExUnit.Parameterized.Params do
 
   defp escape_values(values) do
     values
-    |> Tuple.to_list
+    |> Tuple.to_list()
     |> Enum.map(fn x ->
       case x do
         value when is_map(value) -> Macro.escape(x)
diff --git a/lib/ex_parameterized/params_callback.ex b/lib/ex_parameterized/params_callback.ex
index dae33b0..a40461e 100644
--- a/lib/ex_parameterized/params_callback.ex
+++ b/lib/ex_parameterized/params_callback.ex
@@ -58,7 +58,7 @@ defmodule ExUnit.Parameterized.ParamsCallback do
 
   # Quote literals case : http://elixir-lang.org/docs/master/elixir/Kernel.SpecialForms.html#quote/2
   defp test_with(desc, context, fun, {{param_desc, values}, num}) when is_atom(param_desc) do
-    run("'#{desc}': '#{param_desc}': number of #{num}", context, fun, Tuple.to_list(values))
+    run("'#{desc}': '#{param_desc}': number of #{num}", context, fun, escape_values(values))
   end
 
   defp test_with(desc, context, fun, {{_, _, values}, num}),
@@ -69,7 +69,7 @@ defmodule ExUnit.Parameterized.ParamsCallback do
 
   # Quote literals case : http://elixir-lang.org/docs/master/elixir/Kernel.SpecialForms.html#quote/2
   defp test_with(desc, context, fun, {values, num}),
-    do: run("'#{desc}': number of #{num}", context, fun, Tuple.to_list(values))
+    do: run("'#{desc}': number of #{num}", context, fun, escape_values(values))
 
   defp run(desc, context, fun, params) do
     quote do
@@ -88,4 +88,15 @@ defmodule ExUnit.Parameterized.ParamsCallback do
   defp param_with_index(_) do
     raise(ArgumentError, message: "Unsupported format")
   end
+
+  defp escape_values(values) do
+    values
+    |> Tuple.to_list()
+    |> Enum.map(fn x ->
+      case x do
+        value when is_map(value) -> Macro.escape(x)
+        _ -> x
+      end
+    end)
+  end
 end
diff --git a/test/ex_parameterized_callback_test.exs b/test/ex_parameterized_callback_test.exs
index cab8e84..e06bfc1 100644
--- a/test/ex_parameterized_callback_test.exs
+++ b/test/ex_parameterized_callback_test.exs
@@ -166,4 +166,13 @@ defmodule ExParameterizedParamsCallbackTest do
       {make.(1)}
     ]
   end
+
+  test_with_params "with map as second parameter", context, fn a, m ->
+    assert a == "some"
+    assert m.a == "world"
+  end do
+    [
+      {"some", %{a: context[:hello], b: 2, c: 3}}
+    ]
+  end
 end