diff --git a/SafeExamBrowser.Contracts/Core/OperationModel/Events/ActionRequiredEventArgs.cs b/SafeExamBrowser.Contracts/Core/OperationModel/Events/ActionRequiredEventArgs.cs
index 729d1c41..61bd0f60 100644
--- a/SafeExamBrowser.Contracts/Core/OperationModel/Events/ActionRequiredEventArgs.cs
+++ b/SafeExamBrowser.Contracts/Core/OperationModel/Events/ActionRequiredEventArgs.cs
@@ -11,7 +11,7 @@ namespace SafeExamBrowser.Contracts.Core.OperationModel.Events
 	/// <summary>
 	/// Base class for all event arguments used for <see cref="IOperationSequence.ProgressChanged"/>.
 	/// </summary>
-	public class ActionRequiredEventArgs
+	public abstract class ActionRequiredEventArgs
 	{
 	}
 }
diff --git a/SafeExamBrowser.Core.UnitTests/OperationModel/OperationSequenceTests.cs b/SafeExamBrowser.Core.UnitTests/OperationModel/OperationSequenceTests.cs
index ab2cee5a..7070eab3 100644
--- a/SafeExamBrowser.Core.UnitTests/OperationModel/OperationSequenceTests.cs
+++ b/SafeExamBrowser.Core.UnitTests/OperationModel/OperationSequenceTests.cs
@@ -11,6 +11,8 @@ using System.Collections.Generic;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Moq;
 using SafeExamBrowser.Contracts.Core.OperationModel;
+using SafeExamBrowser.Contracts.Core.OperationModel.Events;
+using SafeExamBrowser.Contracts.I18n;
 using SafeExamBrowser.Contracts.Logging;
 using SafeExamBrowser.Core.OperationModel;
 
@@ -54,6 +56,47 @@ namespace SafeExamBrowser.Core.UnitTests.OperationModel
 			operationC.Verify(o => o.Perform(), Times.Once);
 		}
 
+		[TestMethod]
+		public void MustCorrectlyPropagateEventSubscription()
+		{
+			var actionRequiredCalled = false;
+			var actionRequiredHandler = new ActionRequiredEventHandler(args => actionRequiredCalled = true);
+			var statusChangedCalled = false;
+			var statusChangedHandler = new StatusChangedEventHandler(t => statusChangedCalled = true);
+			var operationA = new Mock<IOperation>();
+			var operationB = new Mock<IOperation>();
+			var operationC = new Mock<IOperation>();
+			var operations = new Queue<IOperation>();
+
+			operationA.Setup(o => o.Perform()).Returns(OperationResult.Success);
+			operationB.Setup(o => o.Perform()).Returns(OperationResult.Success).Raises(o => o.ActionRequired += null, new Mock<ActionRequiredEventArgs>().Object);
+			operationC.Setup(o => o.Perform()).Returns(OperationResult.Success).Raises(o => o.StatusChanged += null, default(TextKey));
+
+			operations.Enqueue(operationA.Object);
+			operations.Enqueue(operationB.Object);
+			operations.Enqueue(operationC.Object);
+
+			var sut = new OperationSequence(loggerMock.Object, operations);
+
+			sut.ActionRequired += actionRequiredHandler;
+			sut.StatusChanged += statusChangedHandler;
+
+			sut.TryPerform();
+
+			Assert.IsTrue(actionRequiredCalled);
+			Assert.IsTrue(statusChangedCalled);
+
+			actionRequiredCalled = false;
+			statusChangedCalled = false;
+			sut.ActionRequired -= actionRequiredHandler;
+			sut.StatusChanged -= statusChangedHandler;
+
+			sut.TryPerform();
+
+			Assert.IsFalse(actionRequiredCalled);
+			Assert.IsFalse(statusChangedCalled);
+		}
+
 		#region Perform Tests
 
 		[TestMethod]
diff --git a/SafeExamBrowser.Core.UnitTests/Operations/LazyInitializationOperationTests.cs b/SafeExamBrowser.Core.UnitTests/Operations/LazyInitializationOperationTests.cs
index 18d643e5..ed33a167 100644
--- a/SafeExamBrowser.Core.UnitTests/Operations/LazyInitializationOperationTests.cs
+++ b/SafeExamBrowser.Core.UnitTests/Operations/LazyInitializationOperationTests.cs
@@ -113,7 +113,7 @@ namespace SafeExamBrowser.Core.UnitTests.Operations
 
 			sut.Perform();
 
-			operationMock.Raise(o => o.ActionRequired += null, new ActionRequiredEventArgs());
+			operationMock.Raise(o => o.ActionRequired += null, new Mock<ActionRequiredEventArgs>().Object);
 			operationMock.Raise(o => o.StatusChanged += null, default(TextKey));
 
 			Assert.AreEqual(1, actionRequired);
@@ -122,7 +122,7 @@ namespace SafeExamBrowser.Core.UnitTests.Operations
 			sut.ActionRequired -= actionRequiredHandler;
 			sut.StatusChanged -= statusChangedHandler;
 
-			operationMock.Raise(o => o.ActionRequired += null, new ActionRequiredEventArgs());
+			operationMock.Raise(o => o.ActionRequired += null, new Mock<ActionRequiredEventArgs>().Object);
 			operationMock.Raise(o => o.StatusChanged += null, default(TextKey));
 
 			Assert.AreEqual(1, actionRequired);
@@ -131,7 +131,7 @@ namespace SafeExamBrowser.Core.UnitTests.Operations
 			sut.ActionRequired += actionRequiredHandler;
 			sut.StatusChanged += statusChangedHandler;
 
-			operationMock.Raise(o => o.ActionRequired += null, new ActionRequiredEventArgs());
+			operationMock.Raise(o => o.ActionRequired += null, new Mock<ActionRequiredEventArgs>().Object);
 			operationMock.Raise(o => o.StatusChanged += null, default(TextKey));
 
 			Assert.AreEqual(2, actionRequired);