diff --git a/lib/membrane_mp4/demuxer/isom.ex b/lib/membrane_mp4/demuxer/isom.ex
index 26ea986..0dd03a3 100644
--- a/lib/membrane_mp4/demuxer/isom.ex
+++ b/lib/membrane_mp4/demuxer/isom.ex
@@ -40,7 +40,7 @@ defmodule Membrane.MP4.Demuxer.ISOM do
       any_of(
         %Membrane.AAC{config: {:esds, _esds}},
         %Membrane.H264{
-          stream_structure: {:avc1, _dcr},
+          stream_structure: {_avc, _dcr},
           alignment: :au
         },
         %Membrane.H265{
diff --git a/lib/membrane_mp4/muxer/isom.ex b/lib/membrane_mp4/muxer/isom.ex
index 2e1169c..0c55c4b 100644
--- a/lib/membrane_mp4/muxer/isom.ex
+++ b/lib/membrane_mp4/muxer/isom.ex
@@ -17,7 +17,7 @@ defmodule Membrane.MP4.Muxer.ISOM do
       any_of(
         %Membrane.AAC{config: {:esds, _esds}},
         %Membrane.H264{
-          stream_structure: {:avc1, _dcr},
+          stream_structure: {_avc, _dcr},
           alignment: :au
         },
         %Membrane.H265{
@@ -96,25 +96,28 @@ defmodule Membrane.MP4.Muxer.ISOM do
   @impl true
   def handle_stream_format(
         Pad.ref(:input, pad_ref) = pad,
-        stream_format,
+        %type{} = stream_format,
         ctx,
         state
       ) do
-    cond do
+    case ctx.pads[pad].stream_format do
       # Handle receiving the first stream format on the given pad
-      is_nil(ctx.pads[pad].stream_format) ->
+      nil ->
         update_in(state, [:pad_to_track, pad_ref], fn track_id ->
           Track.new(track_id, stream_format, state.chunk_duration)
         end)
 
-      # Handle receiving all but the first stream format on the given pad,
-      # when stream format is duplicated - ignore
-      ctx.pads[pad].stream_format == stream_format ->
+      # Handle receiving a stream format of the same type
+      %^type{} ->
         state
 
       # otherwise we can assume that output will be corrupted
-      true ->
-        raise "ISOM Muxer doesn't support variable parameters"
+      previos_format ->
+        raise """
+        Unsupported stream_format change on pad #{inspect(pad_ref)}, \
+        previous format: #{inspect(previos_format)}
+        new format: #{inspect(stream_format)}
+        """
     end
     |> then(&{[], &1})
   end
diff --git a/test/fixtures/isom/ref_video_vp.mp4 b/test/fixtures/isom/ref_video_vp.mp4
new file mode 100644
index 0000000..b64747d
Binary files /dev/null and b/test/fixtures/isom/ref_video_vp.mp4 differ
diff --git a/test/membrane_mp4/muxer/isom/integration_test.exs b/test/membrane_mp4/muxer/isom/integration_test.exs
index f3f74a8..0424798 100644
--- a/test/membrane_mp4/muxer/isom/integration_test.exs
+++ b/test/membrane_mp4/muxer/isom/integration_test.exs
@@ -62,6 +62,24 @@ defmodule Membrane.MP4.Muxer.ISOM.IntegrationTest do
       perform_test(pid, "video")
     end
 
+    test "variable parameters H264 track" do
+      prepare_test("video")
+
+      structure = [
+        child(:file, %Membrane.File.Source{location: "test/fixtures/in_video_vp.h264"})
+        |> child(:parser, %Membrane.H264.Parser{
+          generate_best_effort_timestamps: %{framerate: {30, 1}},
+          output_stream_structure: :avc3
+        })
+        |> child(:muxer, %Membrane.MP4.Muxer.ISOM{chunk_duration: Time.seconds(1)})
+        |> child(:sink, %Membrane.File.Sink{location: out_path_for("video_vp")})
+      ]
+
+      pid = Pipeline.start_link_supervised!(spec: structure)
+
+      perform_test(pid, "video_vp")
+    end
+
     test "single H265 track" do
       prepare_test("video_hevc")
 
@@ -210,58 +228,4 @@ defmodule Membrane.MP4.Muxer.ISOM.IntegrationTest do
       perform_test(pid, "two_tracks_fast_start")
     end
   end
-
-  describe "When fed a variable parameter h264 stream, Muxer.ISOM should" do
-    test "raise when stream format's inband_parameters are not used" do
-      structure = [
-        child(:file, %Membrane.File.Source{location: "test/fixtures/in_video_vp.h264"})
-        |> child(:parser, %Membrane.H264.Parser{
-          generate_best_effort_timestamps: %{framerate: {30, 1}},
-          output_stream_structure: :avc1
-        })
-        |> child(:muxer, %Membrane.MP4.Muxer.ISOM{
-          chunk_duration: Time.seconds(1),
-          fast_start: true
-        })
-        |> child(:sink, Membrane.Fake.Sink.Buffers)
-      ]
-
-      {:ok, _supervisor_pid, pid} = Pipeline.start(spec: structure)
-      monitor_ref = Process.monitor(pid)
-
-      assert_receive {:DOWN, ^monitor_ref, :process, ^pid,
-                      {:membrane_child_crash, :muxer,
-                       {%RuntimeError{
-                          message: "ISOM Muxer doesn't support variable parameters"
-                        }, _stacktrace}}},
-                     1_000
-    end
-  end
-
-  describe "ctts table" do
-    test "should not be stored when dts and pts values are equal" do
-      prepare_test("video")
-
-      structure = [
-        child(:file, %Membrane.File.Source{location: "test/fixtures/in_video.h264"})
-        |> child(:parser, %Membrane.H264.Parser{
-          generate_best_effort_timestamps: %{framerate: {30, 1}, add_dts_offset: false},
-          output_stream_structure: :avc1
-        })
-        |> child(:muxer, %Membrane.MP4.Muxer.ISOM{chunk_duration: Time.seconds(1)})
-        |> child(:sink, %Membrane.File.Sink{location: out_path_for("video")})
-      ]
-
-      pid = Pipeline.start_link_supervised!(spec: structure)
-
-      assert_end_of_stream(pid, :sink, :input)
-      refute_sink_buffer(pid, :sink, _buffer, 0)
-
-      assert :ok == Pipeline.terminate(pid)
-
-      assert {parsed_out, <<>>} = out_path_for("video") |> File.read!() |> Container.parse!()
-      assert Container.get_box(parsed_out, [:moov, :trak, :mdia, :minf, :stbl, :stts])
-      refute Container.get_box(parsed_out, [:moov, :trak, :mdia, :minf, :stbl, :ctts])
-    end
-  end
 end