diff --git a/CHANGELOG.md b/CHANGELOG.md
index dfa42737a..420c9e0f8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@
  * Add `:pause_auto_demand` and `:resume_auto_demand` actions. [#586](https://github.com/membraneframework/membrane_core/pull/586)
  * Send `:end_of_stream`, even if it is not preceded by `:start_of_stream`. [#557](https://github.com/membraneframework/membrane_core/pull/577)
  * Fix process leak in starting clocks. [#594](https://github.com/membraneframework/membrane_core/pull/594)
+ * Add child exit reason to the supervisor exit reason. [#595](https://github.com/membraneframework/membrane_core/pull/595)
  
 ## 0.11.0
  * Separate element_name and pad arguments in handle_element_{start, end}_of_stream signature [#219](https://github.com/membraneframework/membrane_core/issues/219)
diff --git a/lib/membrane/core/parent/child_life_controller.ex b/lib/membrane/core/parent/child_life_controller.ex
index b1ddb7389..794c5ea64 100644
--- a/lib/membrane/core/parent/child_life_controller.ex
+++ b/lib/membrane/core/parent/child_life_controller.ex
@@ -681,7 +681,7 @@ defmodule Membrane.Core.Parent.ChildLifeController do
         Terminating.
         """)
 
-        {:error, {:membrane_child_crash, child_name}}
+        {:error, {:membrane_child_crash, child_name, reason}}
     end
   end
 
diff --git a/lib/membrane/testing/assertions.ex b/lib/membrane/testing/assertions.ex
index 30f5f14f3..496f2bf0f 100644
--- a/lib/membrane/testing/assertions.ex
+++ b/lib/membrane/testing/assertions.ex
@@ -405,6 +405,40 @@ defmodule Membrane.Testing.Assertions do
     end
   end
 
+  @doc """
+  Asserts that `Membrane.Testing.Sink` with name `sink_name` entered the playing
+  playback.
+  """
+  defmacro assert_sink_playing(pipeline, sink_name, timeout \\ @default_timeout) do
+    do_sink_playing(&assert_receive_from_pipeline/3, pipeline, sink_name, timeout)
+  end
+
+  @doc """
+  Asserts that `Membrane.Testing.Sink` with name `sink_name` didn't enter the playing
+  playback.
+  """
+  defmacro refute_sink_playing(pipeline, sink_name, timeout \\ @default_timeout) do
+    do_sink_playing(&refute_receive_from_pipeline/3, pipeline, sink_name, timeout)
+  end
+
+  defp do_sink_playing(assertion, pipeline, sink_name, timeout) do
+    quote do
+      element_name_value = unquote(sink_name)
+
+      unquote(
+        assertion.(
+          pipeline,
+          {:handle_child_notification,
+           {:playing,
+            quote do
+              ^element_name_value
+            end}},
+          timeout
+        )
+      )
+    end
+  end
+
   @doc """
   Asserts that `Membrane.Testing.Pipeline` received or is going to receive start_of_stream
   notification from the element with a name `element_name` within the `timeout` period
diff --git a/lib/membrane/testing/sink.ex b/lib/membrane/testing/sink.ex
index 9b5923b24..5b036fdda 100644
--- a/lib/membrane/testing/sink.ex
+++ b/lib/membrane/testing/sink.ex
@@ -52,13 +52,16 @@ defmodule Membrane.Testing.Sink do
   end
 
   @impl true
-  def handle_playing(_context, %{autodemand: true} = state),
-    do: {[demand: :input], state}
+  def handle_playing(_ctx, state) do
+    actions =
+      notify(:playing) ++
+        if(state.autodemand, do: [demand: :input], else: [])
 
-  def handle_playing(_context, state), do: {[], state}
+    {actions, state}
+  end
 
   @impl true
-  def handle_event(:input, event, _context, state) do
+  def handle_event(:input, event, _ctx, state) do
     {notify({:event, event}), state}
   end
 
diff --git a/test/membrane/integration/auto_demands_test.exs b/test/membrane/integration/auto_demands_test.exs
index 91cd114f0..18bdd7b71 100644
--- a/test/membrane/integration/auto_demands_test.exs
+++ b/test/membrane/integration/auto_demands_test.exs
@@ -96,6 +96,8 @@ defmodule Membrane.Integration.AutoDemandsTest do
         ]
       )
 
+    assert_sink_playing(pipeline, :right_sink)
+
     Pipeline.message_child(pipeline, :right_sink, {:make_demand, 1000})
 
     Enum.each(1..1000, fn payload ->
@@ -191,7 +193,7 @@ defmodule Membrane.Integration.AutoDemandsTest do
 
     @impl true
     def handle_playing(_ctx, state) do
-      {[stream_format: {:output, %StreamFormat{}}], state}
+      {[stream_format: {:output, %StreamFormat{}}, notify_parent: :playing], state}
     end
   end
 
@@ -204,6 +206,8 @@ defmodule Membrane.Integration.AutoDemandsTest do
           |> child(:sink, Sink)
       )
 
+    assert_pipeline_notified(pipeline, :source, :playing)
+
     buffers = Enum.map(1..10, &%Membrane.Buffer{payload: &1})
     Pipeline.message_child(pipeline, :source, buffer: {:output, buffers})
 
@@ -232,9 +236,14 @@ defmodule Membrane.Integration.AutoDemandsTest do
 
     Process.monitor(pipeline)
 
+    assert_pipeline_notified(pipeline, :source, :playing)
+
     buffers = Enum.map(1..100_000, &%Membrane.Buffer{payload: &1})
     Pipeline.message_child(pipeline, :source, buffer: {:output, buffers})
-    assert_receive({:DOWN, _ref, :process, ^pipeline, {:membrane_child_crash, :sink}})
+
+    assert_receive(
+      {:DOWN, _ref, :process, ^pipeline, {:membrane_child_crash, :sink, _sink_reason}}
+    )
   end
 
   defp reduce_link(link, enum, fun) do
diff --git a/test/membrane/integration/child_pad_removed_test.exs b/test/membrane/integration/child_pad_removed_test.exs
index 6ef6d87f2..a558e6a47 100644
--- a/test/membrane/integration/child_pad_removed_test.exs
+++ b/test/membrane/integration/child_pad_removed_test.exs
@@ -40,9 +40,12 @@ defmodule Membrane.Integration.ChildPadRemovedTest do
     def_options test_process: [spec: pid()]
 
     @impl true
-    def handle_init(ctx, opts) do
-      send(opts.test_process, {:init, ctx.name})
-      {[], Map.from_struct(opts)}
+    def handle_init(_ctx, opts), do: {[], Map.from_struct(opts)}
+
+    @impl true
+    def handle_playing(ctx, state) do
+      send(state.test_process, {:playing, ctx.name})
+      {[], state}
     end
   end
 
@@ -161,7 +164,7 @@ defmodule Membrane.Integration.ChildPadRemovedTest do
           ] do
         pipeline = start_pipeline!(DynamicBin, StaticSink)
 
-        assert_receive {:init, :sink}
+        assert_receive {:playing, :sink}
         sink_pid = Testing.Pipeline.get_child_pid!(pipeline, :sink)
         monitor_ref = Process.monitor(sink_pid)
 
@@ -183,7 +186,7 @@ defmodule Membrane.Integration.ChildPadRemovedTest do
           ] do
         pipeline = start_link_pipeline!(DynamicBin, StaticSink, remove_children: :sink)
 
-        assert_receive {:init, :sink}
+        assert_receive {:playing, :sink}
         sink_pid = Testing.Pipeline.get_child_pid!(pipeline, :sink)
         monitor_ref = Process.monitor(sink_pid)
 
diff --git a/test/membrane/integration/defer_setup_test.exs b/test/membrane/integration/defer_setup_test.exs
index 75bb82cc6..f058cb013 100644
--- a/test/membrane/integration/defer_setup_test.exs
+++ b/test/membrane/integration/defer_setup_test.exs
@@ -132,7 +132,9 @@ defmodule Membrane.Integration.DeferSetupTest do
 
     monitor_ref = Process.monitor(pipeline)
     complete_child_setup(pipeline, :bin_2)
-    assert_receive {:DOWN, ^monitor_ref, :process, ^pipeline, {:membrane_child_crash, :bin_2}}
+
+    assert_receive {:DOWN, ^monitor_ref, :process, ^pipeline,
+                    {:membrane_child_crash, :bin_2, _bin_exit_reason}}
   end
 
   defp complete_child_setup(pipeline, child) do
diff --git a/test/membrane/integration/demands_test.exs b/test/membrane/integration/demands_test.exs
index 8b42d4279..ea9880c56 100644
--- a/test/membrane/integration/demands_test.exs
+++ b/test/membrane/integration/demands_test.exs
@@ -20,6 +20,8 @@ defmodule Membrane.Integration.DemandsTest do
   end
 
   defp test_pipeline(pid) do
+    assert_sink_playing(pid, :sink)
+
     demand = 500
     Pipeline.message_child(pid, :sink, {:make_demand, demand})
 
@@ -172,6 +174,11 @@ defmodule Membrane.Integration.DemandsTest do
     @impl true
     def handle_init(_ctx, _opts), do: {[], %{counter: 0}}
 
+    @impl true
+    def handle_playing(_ctx, state) do
+      {[notify_parent: :playing], state}
+    end
+
     @impl true
     def handle_buffer(:input, _buffer, _ctx, state) do
       {[], Map.update!(state, :counter, &(&1 + 1))}
@@ -189,44 +196,6 @@ defmodule Membrane.Integration.DemandsTest do
     end
   end
 
-  test "actions :pause_auto_demand and :resume_auto_demand" do
-    pipeline =
-      Testing.Pipeline.start_link_supervised!(
-        spec:
-          child(RedemandingSource)
-          |> via_in(:input, auto_demand_size: 10)
-          |> child(:sink, PausingSink)
-      )
-
-    # time for pipeline to start playing
-    Process.sleep(500)
-
-    for _i <- 1..10 do
-      # during sleep below source should send around 100 buffers
-      Process.sleep(100 * RedemandingSource.sleep_time())
-
-      Testing.Pipeline.execute_actions(pipeline, notify_child: {:sink, :pause_auto_demand})
-
-      assert_pipeline_notified(pipeline, :sink, {:buff_no, buff_no})
-      # sink should receive around 100 buffers, but the boundary is set to 70, in case of eg.
-      # slowdown of the source when running all tests in the project asynchronously
-      assert buff_no > 70
-
-      # during sleep below source should send up to about auto_demand_size = 10 buffers
-      Process.sleep(100 * RedemandingSource.sleep_time())
-
-      Testing.Pipeline.execute_actions(pipeline, notify_child: {:sink, :resume_auto_demand})
-
-      assert_pipeline_notified(pipeline, :sink, {:buff_no, buff_no})
-      # sink should probably receive between 5 and 15 buffers, but the boundary is set to 25,
-      # to handle the case when eg. there is a delay in receiving the notification from the
-      # pipeline by the :sink
-      assert buff_no < 25
-    end
-
-    Testing.Pipeline.terminate(pipeline)
-  end
-
   defmodule Funnel do
     use Membrane.Filter
 
@@ -293,4 +262,51 @@ defmodule Membrane.Integration.DemandsTest do
 
     Testing.Pipeline.terminate(pipeline)
   end
+
+  defmodule Sync do
+    use Bunch
+    use ExUnit.Case, async: false
+
+    alias Membrane.Integration.DemandsTest.{PausingSink, RedemandingSource}
+
+    test "actions :pause_auto_demand and :resume_auto_demand" do
+      pipeline =
+        Testing.Pipeline.start_link_supervised!(
+          spec:
+            child(RedemandingSource)
+            |> via_in(:input, auto_demand_size: 10)
+            |> child(:sink, PausingSink)
+        )
+
+      assert_sink_playing(pipeline, :sink)
+
+      # time for pipeline to start playing
+      Process.sleep(1000)
+
+      for i <- 1..10 do
+        # during sleep below source should send around 100 buffers
+        Process.sleep(100 * RedemandingSource.sleep_time())
+
+        Testing.Pipeline.execute_actions(pipeline, notify_child: {:sink, :pause_auto_demand})
+
+        assert_pipeline_notified(pipeline, :sink, {:buff_no, buff_no})
+        # sink should receive around 100 buffers, but the boundary is set to 65, in case of eg.
+        # slowdown of the source when running all tests in the project asynchronously
+        if i != 1, do: assert(buff_no > 65)
+
+        # during sleep below source should send up to about auto_demand_size = 10 buffers
+        Process.sleep(100 * RedemandingSource.sleep_time())
+
+        Testing.Pipeline.execute_actions(pipeline, notify_child: {:sink, :resume_auto_demand})
+
+        assert_pipeline_notified(pipeline, :sink, {:buff_no, buff_no})
+        # sink should probably receive between 5 and 15 buffers, but the boundary is set to 25,
+        # to handle the case when eg. there is a delay in receiving the notification from the
+        # pipeline by the :sink
+        assert buff_no < 25
+      end
+
+      Testing.Pipeline.terminate(pipeline)
+    end
+  end
 end
diff --git a/test/membrane/integration/links_validation_test.exs b/test/membrane/integration/links_validation_test.exs
index ff301afdc..9f69e2f38 100644
--- a/test/membrane/integration/links_validation_test.exs
+++ b/test/membrane/integration/links_validation_test.exs
@@ -126,7 +126,8 @@ defmodule Membrane.LinksValidationTest do
 
       Pipeline.execute_actions(pipeline, spec: spec)
 
-      assert_receive({:DOWN, ^ref, :process, ^pipeline, {%Membrane.LinkError{}, _stacktrace}})
+      assert_receive {:DOWN, ^ref, :process, ^pipeline, {%Membrane.LinkError{}, _stacktrace}},
+                     1000
     end
   end
 end
diff --git a/test/membrane/integration/toilet_forwarding_test.exs b/test/membrane/integration/toilet_forwarding_test.exs
index 3953c5dc5..1f240dfff 100644
--- a/test/membrane/integration/toilet_forwarding_test.exs
+++ b/test/membrane/integration/toilet_forwarding_test.exs
@@ -222,6 +222,8 @@ defmodule Membrane.Integration.ToiletForwardingTest do
 
     pipeline = Testing.Pipeline.start_link_supervised!(spec: spec)
 
+    assert_sink_playing(pipeline, :sink)
+
     buffers =
       1..4000
       |> Enum.map(fn i -> %Membrane.Buffer{payload: <<i::64>>} end)
diff --git a/test/membrane/pipeline_supervisor_test.exs b/test/membrane/pipeline_supervisor_test.exs
index cdaf6605e..688506925 100644
--- a/test/membrane/pipeline_supervisor_test.exs
+++ b/test/membrane/pipeline_supervisor_test.exs
@@ -23,7 +23,7 @@ defmodule Membrane.PipelineSupervisorTest do
     assert_receive {:DOWN, ^supervisor_monitor_ref, _process, _pid, ^exit_reason}
   end
 
-  test "Pipeline supervisor exits with {:membrane_child_crash, child_name} when pipeline's child crashes" do
+  test "Pipeline supervisor exits with {:membrane_child_crash, child_name, child_exit_reason} when pipeline's child crashes" do
     defmodule MyElement do
       use Membrane.Endpoint
 
@@ -44,7 +44,7 @@ defmodule Membrane.PipelineSupervisorTest do
     element_exit_reason = :custom_exit_reason
     Process.exit(element, element_exit_reason)
 
-    pipeline_exit_reason = {:membrane_child_crash, :element}
+    pipeline_exit_reason = {:membrane_child_crash, :element, element_exit_reason}
 
     assert_receive {:DOWN, ^element_monitor_ref, _process, _pid, ^element_exit_reason}
     assert_receive {:DOWN, ^pipeline_monitor_ref, _process, _pid, ^pipeline_exit_reason}
diff --git a/test/membrane/remote_controlled/pipeline_test.exs b/test/membrane/remote_controlled/pipeline_test.exs
index 5a57bbc3d..8e79aeb33 100644
--- a/test/membrane/remote_controlled/pipeline_test.exs
+++ b/test/membrane/remote_controlled/pipeline_test.exs
@@ -12,6 +12,8 @@ defmodule Membrane.RCPipelineTest do
     use Membrane.Filter
     alias Membrane.Buffer
 
+    require Membrane.Logger
+
     def_output_pad :output, flow_control: :manual, accepted_format: _any, availability: :always
 
     def_input_pad :input,
@@ -73,10 +75,11 @@ defmodule Membrane.RCPipelineTest do
 
       # TEST
       assert_receive %RCMessage.Notification{
-        from: ^pipeline,
-        element: :b,
-        data: %Membrane.Buffer{payload: "test"}
-      }
+                       from: ^pipeline,
+                       element: :b,
+                       data: %Membrane.Buffer{payload: "test"}
+                     },
+                     2000
 
       assert_receive %RCMessage.StartOfStream{from: ^pipeline, element: :b, pad: :input}
 
@@ -91,7 +94,7 @@ defmodule Membrane.RCPipelineTest do
       RCPipeline.exec_actions(pipeline, spec: @pipeline_spec)
 
       # TEST
-      assert_receive %RCMessage.EndOfStream{from: ^pipeline, element: :b, pad: :input}
+      assert_receive %RCMessage.EndOfStream{from: ^pipeline, element: :b, pad: :input}, 2000
 
       assert_receive %RCMessage.EndOfStream{from: ^pipeline, element: :c, pad: :input}
 
diff --git a/test/membrane/sync_test.exs b/test/membrane/sync_test.exs
index d750046fa..e57168bdf 100644
--- a/test/membrane/sync_test.exs
+++ b/test/membrane/sync_test.exs
@@ -1,6 +1,6 @@
 defmodule Membrane.SyncTest do
   use Bunch
-  use ExUnit.Case, async: true
+  use ExUnit.Case, async: false
 
   @module Membrane.Sync
 
diff --git a/test/membrane/utility_supervisor_test.exs b/test/membrane/utility_supervisor_test.exs
index 0aba5ce10..ed182b094 100644
--- a/test/membrane/utility_supervisor_test.exs
+++ b/test/membrane/utility_supervisor_test.exs
@@ -7,6 +7,8 @@ defmodule Membrane.UtilitySupervisorTest do
   alias Membrane.Testing
 
   test "Utility supervisor terminates utility when element exits" do
+    Process.register(self(), :utility_supervisor_test_process)
+
     defmodule TestFilter do
       use Membrane.Filter
 
@@ -16,7 +18,7 @@ defmodule Membrane.UtilitySupervisorTest do
           ctx.utility_supervisor,
           {Task,
            fn ->
-             Process.register(self(), :utility_supervisor_test_task)
+             send(:utility_supervisor_test_process, {:task_pid, self()})
              Process.sleep(:infinity)
            end}
         )
@@ -28,8 +30,11 @@ defmodule Membrane.UtilitySupervisorTest do
     pipeline = Testing.Pipeline.start_supervised!(spec: [child(:filter, TestFilter)])
 
     assert_pipeline_notified(pipeline, :filter, :setup)
-    monitor = Process.monitor(:utility_supervisor_test_task)
+    assert_receive {:task_pid, task_pid}
+
+    monitor_ref = Process.monitor(task_pid)
+
     Testing.Pipeline.terminate(pipeline)
-    assert_receive {:DOWN, ^monitor, :process, _pid, :shutdown}
+    assert_receive {:DOWN, ^monitor_ref, :process, _pid, :shutdown}
   end
 end