diff --git a/aiida/engine/processes/workchains/restart.py b/aiida/engine/processes/workchains/restart.py
index 481f056755..2be440d530 100644
--- a/aiida/engine/processes/workchains/restart.py
+++ b/aiida/engine/processes/workchains/restart.py
@@ -240,7 +240,7 @@ def inspect_process(self):  # pylint: disable=inconsistent-return-statements,too
 
         # Here either the process finished successful or at least one handler returned a report so it can no longer be
         # considered to be an unhandled failed process and therefore we reset the flag
-        self.ctx.unhandled_failure = True
+        self.ctx.unhandled_failure = False
 
         # If at least one handler returned a report, the action depends on its exit code and that of the process itself
         if last_report:
diff --git a/tests/conftest.py b/tests/conftest.py
index 84afd04efd..4f0b661230 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -91,3 +91,56 @@ def _generate_calc_job(folder, entry_point_name, inputs=None):
         return calc_info
 
     return _generate_calc_job
+
+
+@pytest.fixture
+def generate_work_chain():
+    """Generate an instance of a `WorkChain`."""
+
+    def _generate_work_chain(entry_point, inputs=None):
+        """Generate an instance of a `WorkChain` with the given entry point and inputs.
+
+        :param entry_point: entry point name of the work chain subclass.
+        :param inputs: inputs to be passed to process construction.
+        :return: a `WorkChain` instance.
+        """
+        from aiida.engine.utils import instantiate_process
+        from aiida.manage.manager import get_manager
+        from aiida.plugins import WorkflowFactory
+
+        inputs = inputs or {}
+        process_class = WorkflowFactory(entry_point) if isinstance(entry_point, str) else entry_point
+        runner = get_manager().get_runner()
+        process = instantiate_process(runner, process_class, **inputs)
+
+        return process
+
+    return _generate_work_chain
+
+
+@pytest.fixture
+def generate_calculation_node():
+    """Generate an instance of a `CalculationNode`."""
+    from aiida.engine import ProcessState
+
+    def _generate_calculation_node(process_state=ProcessState.FINISHED, exit_status=None):
+        """Generate an instance of a `CalculationNode`..
+
+        :param process_state: state to set
+        :param exit_status: optional exit status, will be set to `0` if `process_state` is `ProcessState.FINISHED`
+        :return: a `CalculationNode` instance.
+        """
+        from aiida.orm import CalculationNode
+
+        if process_state is ProcessState.FINISHED and exit_status is None:
+            exit_status = 0
+
+        node = CalculationNode()
+        node.set_process_state(process_state)
+
+        if exit_status is not None:
+            node.set_exit_status(exit_status)
+
+        return node
+
+    return _generate_calculation_node
diff --git a/tests/engine/processes/workchains/test_restart.py b/tests/engine/processes/workchains/test_restart.py
index 5cbabaa73b..77de70517d 100644
--- a/tests/engine/processes/workchains/test_restart.py
+++ b/tests/engine/processes/workchains/test_restart.py
@@ -8,44 +8,99 @@
 # For further information please visit http://www.aiida.net               #
 ###########################################################################
 """Tests for `aiida.engine.processes.workchains.restart` module."""
-from aiida.backends.testbase import AiidaTestCase
-from aiida.engine.processes.workchains.restart import BaseRestartWorkChain
-from aiida.engine.processes.workchains.utils import process_handler
+# pylint: disable=invalid-name
+import pytest
 
+from aiida.engine import CalcJob, BaseRestartWorkChain, process_handler, ProcessState, ProcessHandlerReport, ExitCode
 
-class TestBaseRestartWorkChain(AiidaTestCase):
-    """Tests for the `BaseRestartWorkChain` class."""
 
-    @staticmethod
-    def test_is_process_handler():
-        """Test the `BaseRestartWorkChain.is_process_handler` class method."""
+class SomeWorkChain(BaseRestartWorkChain):
+    """Dummy class."""
 
-        class SomeWorkChain(BaseRestartWorkChain):
-            """Dummy class."""
+    _process_class = CalcJob
 
-            @process_handler()
-            def handler_a(self, node):
-                pass
+    @process_handler()
+    def handler_a(self, node):  # pylint: disable=inconsistent-return-statements,no-self-use
+        if node.exit_status == 400:
+            return ProcessHandlerReport()
 
-            def not_a_handler(self, node):
-                pass
+    def not_a_handler(self, node):
+        pass
 
-        assert SomeWorkChain.is_process_handler('handler_a')
-        assert not SomeWorkChain.is_process_handler('not_a_handler')
-        assert not SomeWorkChain.is_process_handler('unexisting_method')
 
-    @staticmethod
-    def test_get_process_handler():
-        """Test the `BaseRestartWorkChain.get_process_handlers` class method."""
+def test_is_process_handler():
+    """Test the `BaseRestartWorkChain.is_process_handler` class method."""
+    assert SomeWorkChain.is_process_handler('handler_a')
+    assert not SomeWorkChain.is_process_handler('not_a_handler')
+    assert not SomeWorkChain.is_process_handler('unexisting_method')
 
-        class SomeWorkChain(BaseRestartWorkChain):
-            """Dummy class."""
 
-            @process_handler
-            def handler_a(self, node):
-                pass
+def test_get_process_handler():
+    """Test the `BaseRestartWorkChain.get_process_handlers` class method."""
+    assert [handler.__name__ for handler in SomeWorkChain.get_process_handlers()] == ['handler_a']
 
-            def not_a_handler(self, node):
-                pass
 
-        assert [handler.__name__ for handler in SomeWorkChain.get_process_handlers()] == ['handler_a']
+@pytest.mark.usefixtures('clear_database_before_test')
+def test_excepted_process(generate_work_chain, generate_calculation_node):
+    """Test that the workchain aborts if the sub process was excepted."""
+    process = generate_work_chain(SomeWorkChain, {})
+    process.setup()
+    process.ctx.children = [generate_calculation_node(ProcessState.EXCEPTED)]
+    assert process.inspect_process() == BaseRestartWorkChain.exit_codes.ERROR_SUB_PROCESS_EXCEPTED  # pylint: disable=no-member
+
+
+@pytest.mark.usefixtures('clear_database_before_test')
+def test_killed_process(generate_work_chain, generate_calculation_node):
+    """Test that the workchain aborts if the sub process was killed."""
+    process = generate_work_chain(SomeWorkChain, {})
+    process.setup()
+    process.ctx.children = [generate_calculation_node(ProcessState.KILLED)]
+    assert process.inspect_process() == BaseRestartWorkChain.exit_codes.ERROR_SUB_PROCESS_KILLED  # pylint: disable=no-member
+
+
+@pytest.mark.usefixtures('clear_database_before_test')
+def test_unhandled_failure(generate_work_chain, generate_calculation_node):
+    """Test the unhandled failure mechanism.
+
+    The workchain should be aborted if there are two consecutive failed sub processes that went unhandled. We simulate
+    it by setting `ctx.unhandled_failure` to True and append two failed process nodes in `ctx.children`.
+    """
+    process = generate_work_chain(SomeWorkChain, {})
+    process.setup()
+    process.ctx.children = [generate_calculation_node(exit_status=100)]
+    assert process.inspect_process() is None
+    assert process.ctx.unhandled_failure is True
+
+    process.ctx.children.append(generate_calculation_node(exit_status=100))
+    assert process.inspect_process() == BaseRestartWorkChain.exit_codes.ERROR_SECOND_CONSECUTIVE_UNHANDLED_FAILURE  # pylint: disable=no-member
+
+
+@pytest.mark.usefixtures('clear_database_before_test')
+def test_unhandled_reset_after_success(generate_work_chain, generate_calculation_node):
+    """Test `ctx.unhandled_failure` is reset to `False` in `inspect_process` after a successful process."""
+    process = generate_work_chain(SomeWorkChain, {})
+    process.setup()
+    process.ctx.children = [generate_calculation_node(exit_status=100)]
+    assert process.inspect_process() is None
+    assert process.ctx.unhandled_failure is True
+
+    process.ctx.children.append(generate_calculation_node(exit_status=0))
+    assert process.inspect_process() is None
+    assert process.ctx.unhandled_failure is False
+
+
+@pytest.mark.usefixtures('clear_database_before_test')
+def test_unhandled_reset_after_handled(generate_work_chain, generate_calculation_node):
+    """Test `ctx.unhandled_failure` is reset to `False` in `inspect_process` after a handled failed process."""
+    process = generate_work_chain(SomeWorkChain, {})
+    process.setup()
+    process.ctx.children = [generate_calculation_node(exit_status=0)]
+    assert process.inspect_process() is None
+    assert process.ctx.unhandled_failure is False
+
+    # Exit status 400 of the last calculation job will be handled and so should reset the flag
+    process.ctx.children.append(generate_calculation_node(exit_status=400))
+    result = process.inspect_process()
+    assert isinstance(result, ExitCode)
+    assert result.status == 0
+    assert process.ctx.unhandled_failure is False