diff --git a/src/Smaragd/ViewModels/DialogModel.cs b/src/Smaragd/ViewModels/DialogModel.cs
index 489627a..6ec8c3f 100644
--- a/src/Smaragd/ViewModels/DialogModel.cs
+++ b/src/Smaragd/ViewModels/DialogModel.cs
@@ -2,7 +2,7 @@
 {
     /// <inheritdoc cref="IDialogModel" />
     public abstract class DialogModel
-        : ValidatingViewModel, IDialogModel
+        : ViewModel, IDialogModel
     {
         private string _title;
 
diff --git a/src/Smaragd/ViewModels/IBindable.cs b/src/Smaragd/ViewModels/IBindable.cs
index f2e4c4e..adaab8d 100644
--- a/src/Smaragd/ViewModels/IBindable.cs
+++ b/src/Smaragd/ViewModels/IBindable.cs
@@ -2,6 +2,7 @@
 
 namespace NKristek.Smaragd.ViewModels
 {
+    /// <inheritdoc cref="INotifyPropertyChanged" />
     /// <summary>
     /// Notifies clients that a property value is changing or has changed.
     /// </summary>
diff --git a/src/Smaragd/ViewModels/IValidatingBindable.cs b/src/Smaragd/ViewModels/IValidatingBindable.cs
new file mode 100644
index 0000000..ba43508
--- /dev/null
+++ b/src/Smaragd/ViewModels/IValidatingBindable.cs
@@ -0,0 +1,13 @@
+using System.ComponentModel;
+
+namespace NKristek.Smaragd.ViewModels
+{
+    /// <inheritdoc cref="IBindable" />
+    /// <summary>
+    /// Notifies clients that errors of a property have changed.
+    /// </summary>
+    public interface IValidatingBindable
+        : IBindable, INotifyDataErrorInfo
+    {
+    }
+}
diff --git a/src/Smaragd/ViewModels/IValidatingViewModel.cs b/src/Smaragd/ViewModels/IValidatingViewModel.cs
deleted file mode 100644
index 4a5caff..0000000
--- a/src/Smaragd/ViewModels/IValidatingViewModel.cs
+++ /dev/null
@@ -1,25 +0,0 @@
-using System.Collections;
-using System.ComponentModel;
-
-namespace NKristek.Smaragd.ViewModels
-{
-    /// <inheritdoc cref="IViewModel" />
-    /// <summary>
-    /// Defines a <see cref="IViewModel"/> which performs validation.
-    /// </summary>
-    public interface IValidatingViewModel
-        : IViewModel, INotifyDataErrorInfo
-    {
-        /// <summary>
-        /// If data is valid.
-        /// </summary>
-        bool IsValid { get; }
-
-        /// <summary>
-        /// Set validation errors of a property.
-        /// </summary>
-        /// <param name="errors">The errors of the property.</param>
-        /// <param name="propertyName">The name of the property.</param>
-        void SetErrors(IEnumerable errors, string propertyName = null);
-    }
-}
\ No newline at end of file
diff --git a/src/Smaragd/ViewModels/IViewModel.cs b/src/Smaragd/ViewModels/IViewModel.cs
index a189f10..238b105 100644
--- a/src/Smaragd/ViewModels/IViewModel.cs
+++ b/src/Smaragd/ViewModels/IViewModel.cs
@@ -5,7 +5,7 @@
     /// Defines properties which are useful for a viewmodel implementation.
     /// </summary>
     public interface IViewModel
-        : IBindable
+        : IValidatingBindable
     {
         /// <summary>
         /// Indicates if a property changed and the change is not persisted.
@@ -26,5 +26,10 @@ public interface IViewModel
         /// Indicates if this <see cref="IViewModel"/> instance is currently being updated.
         /// </summary>
         bool IsUpdating { get; set; }
+        
+        /// <summary>
+        /// If data is valid.
+        /// </summary>
+        bool IsValid { get; }
     }
 }
\ No newline at end of file
diff --git a/src/Smaragd/ViewModels/ValidatingViewModel.cs b/src/Smaragd/ViewModels/ValidatingBindable.cs
similarity index 79%
rename from src/Smaragd/ViewModels/ValidatingViewModel.cs
rename to src/Smaragd/ViewModels/ValidatingBindable.cs
index 9ff87b9..16dd91a 100644
--- a/src/Smaragd/ViewModels/ValidatingViewModel.cs
+++ b/src/Smaragd/ViewModels/ValidatingBindable.cs
@@ -4,26 +4,33 @@
 using System.ComponentModel;
 using System.Linq;
 using System.Runtime.CompilerServices;
-using NKristek.Smaragd.Attributes;
 
 namespace NKristek.Smaragd.ViewModels
 {
-    /// <inheritdoc cref="IValidatingViewModel" />
-    public abstract class ValidatingViewModel
-        : ViewModel, IValidatingViewModel
+    /// <inheritdoc cref="IValidatingBindable" />
+    public abstract class ValidatingBindable
+        : Bindable, IValidatingBindable
     {
         private readonly Dictionary<string, IReadOnlyCollection<object>> _errors = new Dictionary<string, IReadOnlyCollection<object>>();
 
-        #region IValidatingViewModel
-
         /// <inheritdoc />
-        [IsDirtyIgnored]
-        [PropertySource(nameof(HasErrors))]
-        public virtual bool IsValid => !HasErrors;
+        public virtual bool HasErrors => _errors.Count > 0;
 
         /// <inheritdoc />
+        public virtual IEnumerable GetErrors(string propertyName)
+        {
+            if (String.IsNullOrEmpty(propertyName))
+                return _errors.SelectMany(kvp => kvp.Value);
+            return _errors.TryGetValue(propertyName, out var errors) ? errors : Enumerable.Empty<object>();
+        }
+
+        /// <summary>
+        /// Set validation errors of a property.
+        /// </summary>
+        /// <param name="errors">The errors of the property.</param>
+        /// <param name="propertyName">The name of the property.</param>
         /// <exception cref="ArgumentNullException"><paramref name="propertyName"/> is <see langword="null"/> or empty.</exception>
-        public virtual void SetErrors(IEnumerable errors, [CallerMemberName] string propertyName = null)
+        protected virtual void SetErrors(IEnumerable errors, [CallerMemberName] string propertyName = null)
         {
             if (String.IsNullOrEmpty(propertyName))
                 throw new ArgumentNullException(nameof(propertyName));
@@ -44,25 +51,9 @@ public virtual void SetErrors(IEnumerable errors, [CallerMemberName] string prop
             }
         }
 
-        #endregion
-
-        #region INotifyDataErrorInfo
-
-        /// <inheritdoc />
-        [IsDirtyIgnored]
-        public virtual bool HasErrors => _errors.Count > 0;
-
-        /// <inheritdoc />
-        public virtual IEnumerable GetErrors(string propertyName)
-        {
-            if (String.IsNullOrEmpty(propertyName))
-                return _errors.SelectMany(kvp => kvp.Value);
-            return _errors.TryGetValue(propertyName, out var errors) ? errors : Enumerable.Empty<object>();
-        }
-
         /// <inheritdoc />
         public event EventHandler<DataErrorsChangedEventArgs> ErrorsChanged;
-        
+
         /// <summary>
         /// Raises an event on <see cref="INotifyDataErrorInfo.ErrorsChanged"/> to indicate that the validation errors have changed.
         /// </summary>
@@ -71,7 +62,5 @@ protected virtual void NotifyErrorsChanged([CallerMemberName] string propertyNam
         {
             ErrorsChanged?.Invoke(this, new DataErrorsChangedEventArgs(propertyName));
         }
-
-        #endregion
     }
-}
\ No newline at end of file
+}
diff --git a/src/Smaragd/ViewModels/ViewModel.cs b/src/Smaragd/ViewModels/ViewModel.cs
index c2cfa0e..ca58b6e 100644
--- a/src/Smaragd/ViewModels/ViewModel.cs
+++ b/src/Smaragd/ViewModels/ViewModel.cs
@@ -12,7 +12,7 @@ namespace NKristek.Smaragd.ViewModels
 {
     /// <inheritdoc cref="IViewModel" />
     public abstract class ViewModel
-        : Bindable, IViewModel
+        : ValidatingBindable, IViewModel
     {
         private readonly INotificationCache _notificationCache = new NotificationCache();
 
@@ -127,6 +127,15 @@ private void OnChildCollectionChanged(object sender, NotifyCollectionChangedEven
             IsDirty = true;
         }
 
+        /// <inheritdoc />
+        [IsDirtyIgnored]
+        public override bool HasErrors => base.HasErrors;
+
+        /// <inheritdoc />
+        [IsDirtyIgnored]
+        [PropertySource(nameof(HasErrors))]
+        public virtual bool IsValid => !HasErrors;
+
         private bool _isDirty;
 
         /// <inheritdoc />
diff --git a/test/Smaragd.Tests/ViewModels/ValidatingBindableTests.cs b/test/Smaragd.Tests/ViewModels/ValidatingBindableTests.cs
new file mode 100644
index 0000000..808b062
--- /dev/null
+++ b/test/Smaragd.Tests/ViewModels/ValidatingBindableTests.cs
@@ -0,0 +1,207 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using NKristek.Smaragd.ViewModels;
+using Xunit;
+
+namespace NKristek.Smaragd.Tests.ViewModels
+{
+    public class ValidatingBindableTests
+    {
+        private class TestBindable
+            : ValidatingBindable
+        {
+            private int _property;
+
+            public int Property
+            {
+                get => _property;
+                set => SetProperty(ref _property, value);
+            }
+
+            private int _anotherProperty;
+
+            public int AnotherProperty
+            {
+                get => _anotherProperty;
+                set => SetProperty(ref _anotherProperty, value);
+            }
+
+            public void NotifyPropertyChangingExternal(string propertyName)
+            {
+                NotifyPropertyChanging(propertyName);
+            }
+
+            public void NotifyPropertyChangedExternal(string propertyName)
+            {
+                NotifyPropertyChanged(propertyName);
+            }
+
+            public bool HasNotifiedErrorsChanged;
+
+            protected override void NotifyErrorsChanged([CallerMemberName] string propertyName = null)
+            {
+                base.NotifyErrorsChanged(propertyName);
+                HasNotifiedErrorsChanged = true;
+            }
+
+            public void NotifyErrorsChangedExternal(string propertyName)
+            {
+                NotifyErrorsChanged(propertyName);
+            }
+
+            public void SetErrorsExternal(IEnumerable errors, [CallerMemberName] string propertyName = null)
+            {
+                SetErrors(errors, propertyName);
+            }
+        }
+
+        #region SetErrors
+
+        [Fact]
+        public void SetErrors_throws_ArgumentNullException_when_propertyName_is_null()
+        {
+            var viewModel = new TestBindable();
+            Assert.Throws<ArgumentNullException>(() => viewModel.SetErrorsExternal(Enumerable.Empty<string>(), null));
+        }
+
+        [Fact]
+        public void SetErrors_propertyName_is_set_by_CallerMemberName()
+        {
+            var invokedErrorChangedEvents = new List<string>();
+            var viewModel = new TestBindable();
+            viewModel.ErrorsChanged += (sender, args) => invokedErrorChangedEvents.Add(args.PropertyName);
+            viewModel.SetErrorsExternal(Enumerable.Repeat("error", 1));
+            Assert.Contains(nameof(SetErrors_propertyName_is_set_by_CallerMemberName), invokedErrorChangedEvents);
+        }
+
+        [Fact]
+        public void SetErrors_sets_errors_of_property()
+        {
+            var errors = Enumerable.Repeat("error", 1);
+            var viewModel = new TestBindable();
+            viewModel.SetErrorsExternal(errors, nameof(viewModel.Property));
+            Assert.Equal(errors, viewModel.GetErrors(nameof(viewModel.Property)));
+        }
+
+        [Fact]
+        public void SetErrors_null_removes_errors_of_property()
+        {
+            var errors = Enumerable.Repeat("error", 1);
+            var viewModel = new TestBindable();
+            viewModel.SetErrorsExternal(errors, nameof(viewModel.Property));
+            viewModel.SetErrorsExternal(null, nameof(viewModel.Property));
+            Assert.Empty(viewModel.GetErrors(nameof(viewModel.Property)));
+        }
+
+        [Fact]
+        public void SetErrors_empty_collection_removes_errors_of_property()
+        {
+            var errors = Enumerable.Repeat("error", 1);
+            var viewModel = new TestBindable();
+            viewModel.SetErrorsExternal(errors, nameof(viewModel.Property));
+            viewModel.SetErrorsExternal(Enumerable.Empty<string>(), nameof(viewModel.Property));
+            Assert.Empty(viewModel.GetErrors(nameof(viewModel.Property)));
+        }
+
+        [Fact]
+        public void SetErrors_notifies_when_errors_changed()
+        {
+            var viewModel = new TestBindable();
+            Assert.False(viewModel.HasNotifiedErrorsChanged);
+            viewModel.SetErrorsExternal(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
+            Assert.True(viewModel.HasNotifiedErrorsChanged);
+        }
+
+        #endregion
+
+        #region HasErrors
+
+        [Fact]
+        public void HasErrors_is_true_when_validation_errors_exist()
+        {
+            var viewModel = new TestBindable();
+            viewModel.SetErrorsExternal(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
+            Assert.True(viewModel.HasErrors);
+        }
+
+        [Fact]
+        public void HasErrors_is_false_when_no_validation_errors_exist()
+        {
+            var viewModel = new TestBindable();
+            viewModel.SetErrorsExternal(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
+            viewModel.SetErrorsExternal(Enumerable.Empty<string>(), nameof(viewModel.Property));
+            Assert.False(viewModel.HasErrors);
+        }
+
+        [Fact]
+        public void HasErrors_gets_notified_before_errors_change()
+        {
+            var invokedPropertyChangingEvents = new List<string>();
+            var viewModel = new TestBindable();
+            viewModel.PropertyChanging += (sender, args) => invokedPropertyChangingEvents.Add(args.PropertyName);
+            viewModel.SetErrorsExternal(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
+            Assert.Contains(nameof(viewModel.HasErrors), invokedPropertyChangingEvents);
+        }
+
+        [Fact]
+        public void HasErrors_gets_notified_after_errors_change()
+        {
+            var invokedPropertyChangedEvents = new List<string>();
+            var viewModel = new TestBindable();
+            viewModel.PropertyChanged += (sender, args) => invokedPropertyChangedEvents.Add(args.PropertyName);
+            viewModel.SetErrorsExternal(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
+            Assert.Contains(nameof(viewModel.HasErrors), invokedPropertyChangedEvents);
+        }
+
+        #endregion
+
+        #region GetErrors
+
+        [Theory]
+        [InlineData(null, 2)]
+        [InlineData("", 2)]
+        [InlineData(nameof(TestBindable.Property), 1)]
+        [InlineData("NotExistingProperty", 0)]
+        public void GetErrors_with_error(string propertyName, int expectedErrorCount)
+        {
+            var viewModel = new TestBindable();
+            viewModel.SetErrorsExternal(Enumerable.Repeat("Value has to be at least 5.", 1), nameof(TestBindable.Property));
+            viewModel.SetErrorsExternal(Enumerable.Repeat("Value has to be at least 5.", 1), nameof(TestBindable.AnotherProperty));
+            Assert.Equal(Enumerable.Repeat("Value has to be at least 5.", expectedErrorCount), viewModel.GetErrors(propertyName));
+        }
+
+        [Theory]
+        [InlineData(null)]
+        [InlineData("")]
+        [InlineData(nameof(TestBindable.Property))]
+        [InlineData("NotExistingProperty")]
+        public void GetErrors_without_error(string propertyName)
+        {
+            var viewModel = new TestBindable();
+            viewModel.SetErrorsExternal(Enumerable.Repeat("Value has to be at least 5.", 1), nameof(TestBindable.Property));
+            viewModel.SetErrorsExternal(Enumerable.Empty<string>(), nameof(viewModel.Property));
+            Assert.Empty(viewModel.GetErrors(propertyName));
+        }
+
+        #endregion
+
+        #region NotifyErrorsChanged
+
+        [Fact]
+        public void NotifyErrorsChanged_raises_event_on_ErrorsChanged()
+        {
+            var invokedErrorChangedEvents = new List<string>();
+            var viewModel = new TestBindable();
+            viewModel.ErrorsChanged += (sender, args) => invokedErrorChangedEvents.Add(args.PropertyName);
+
+            viewModel.NotifyErrorsChangedExternal(nameof(viewModel.Property));
+
+            Assert.Equal(Enumerable.Repeat(nameof(viewModel.Property), 1), invokedErrorChangedEvents);
+        }
+
+        #endregion
+    }
+}
\ No newline at end of file
diff --git a/test/Smaragd.Tests/ViewModels/ValidatingViewModelTests.cs b/test/Smaragd.Tests/ViewModels/ValidatingViewModelTests.cs
deleted file mode 100644
index 449b2aa..0000000
--- a/test/Smaragd.Tests/ViewModels/ValidatingViewModelTests.cs
+++ /dev/null
@@ -1,281 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.ComponentModel;
-using System.Linq;
-using System.Runtime.CompilerServices;
-using NKristek.Smaragd.ViewModels;
-using Xunit;
-
-namespace NKristek.Smaragd.Tests.ViewModels
-{
-    public class ValidatingViewModelTests
-    {
-        private class TestViewModel
-            : ValidatingViewModel
-        {
-            private int _property;
-
-            public int Property
-            {
-                get => _property;
-                set => SetProperty(ref _property, value);
-            }
-
-            private int _anotherProperty;
-
-            public int AnotherProperty
-            {
-                get => _anotherProperty;
-                set => SetProperty(ref _anotherProperty, value);
-            }
-
-            public void NotifyPropertyChangingExternal(string propertyName)
-            {
-                NotifyPropertyChanging(propertyName);
-            }
-
-            public void NotifyPropertyChangedExternal(string propertyName)
-            {
-                NotifyPropertyChanged(propertyName);
-            }
-
-            public bool HasNotifiedErrorsChanged;
-
-            protected override void NotifyErrorsChanged([CallerMemberName] string propertyName = null)
-            {
-                base.NotifyErrorsChanged(propertyName);
-                HasNotifiedErrorsChanged = true;
-            }
-
-            public void NotifyErrorsChangedExternal(string propertyName)
-            {
-                NotifyErrorsChanged(propertyName);
-            }
-        }
-
-        #region IsValid
-
-        [Fact]
-        public void IsValid_is_false_when_validation_errors_exist()
-        {
-            var viewModel = new TestViewModel();
-            viewModel.SetErrors(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
-            Assert.False(viewModel.IsValid);
-        }
-
-        [Fact]
-        public void IsValid_is_true_when_no_validation_errors_exist()
-        {
-            var viewModel = new TestViewModel();
-            viewModel.SetErrors(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
-            viewModel.SetErrors(Enumerable.Empty<string>(), nameof(viewModel.Property));
-            Assert.True(viewModel.IsValid);
-        }
-
-        [Fact]
-        public void IsValid_does_not_set_IsDirty()
-        {
-            var viewModel = new TestViewModel();
-            viewModel.NotifyPropertyChangedExternal(nameof(viewModel.IsValid));
-            Assert.False(viewModel.IsDirty);
-        }
-
-        [Fact]
-        public void IsValid_gets_notified_by_HasErrors()
-        {
-            var invokedPropertyChangingEvents = new List<string>();
-            var invokedPropertyChangedEvents = new List<string>();
-            var viewModel = new TestViewModel();
-            viewModel.PropertyChanging += (sender, args) => invokedPropertyChangingEvents.Add(args.PropertyName);
-            viewModel.PropertyChanged += (sender, args) => invokedPropertyChangedEvents.Add(args.PropertyName);
-
-            viewModel.NotifyPropertyChangingExternal(nameof(viewModel.HasErrors));
-            viewModel.NotifyPropertyChangedExternal(nameof(viewModel.HasErrors));
-
-            Assert.Contains(nameof(viewModel.IsValid), invokedPropertyChangingEvents);
-            Assert.Contains(nameof(viewModel.IsValid), invokedPropertyChangedEvents);
-        }
-
-        #endregion
-
-        #region SetErrors
-
-        [Fact]
-        public void SetErrors_throws_ArgumentNullException_when_propertyName_is_null()
-        {
-            var viewModel = new TestViewModel();
-            Assert.Throws<ArgumentNullException>(() => viewModel.SetErrors(Enumerable.Empty<string>(), null));
-        }
-
-        [Fact]
-        public void SetErrors_propertyName_is_set_by_CallerMemberName()
-        {
-            var invokedErrorChangedEvents = new List<string>();
-            var viewModel = new TestViewModel();
-            viewModel.ErrorsChanged += (sender, args) => invokedErrorChangedEvents.Add(args.PropertyName);
-            viewModel.SetErrors(Enumerable.Repeat("error", 1));
-            Assert.Contains(nameof(SetErrors_propertyName_is_set_by_CallerMemberName), invokedErrorChangedEvents);
-        }
-
-        [Fact]
-        public void SetErrors_sets_errors_of_property()
-        {
-            var errors = Enumerable.Repeat("error", 1);
-            var viewModel = new TestViewModel();
-            viewModel.SetErrors(errors, nameof(viewModel.Property));
-            Assert.Equal(errors, viewModel.GetErrors(nameof(viewModel.Property)));
-        }
-
-        [Fact]
-        public void SetErrors_null_removes_errors_of_property()
-        {
-            var errors = Enumerable.Repeat("error", 1);
-            var viewModel = new TestViewModel();
-            viewModel.SetErrors(errors, nameof(viewModel.Property));
-            viewModel.SetErrors(null, nameof(viewModel.Property));
-            Assert.Empty(viewModel.GetErrors(nameof(viewModel.Property)));
-        }
-
-        [Fact]
-        public void SetErrors_empty_collection_removes_errors_of_property()
-        {
-            var errors = Enumerable.Repeat("error", 1);
-            var viewModel = new TestViewModel();
-            viewModel.SetErrors(errors, nameof(viewModel.Property));
-            viewModel.SetErrors(Enumerable.Empty<string>(), nameof(viewModel.Property));
-            Assert.Empty(viewModel.GetErrors(nameof(viewModel.Property)));
-        }
-
-        [Fact]
-        public void SetErrors_notifies_when_errors_changed()
-        {
-            var viewModel = new TestViewModel();
-            Assert.False(viewModel.HasNotifiedErrorsChanged);
-            viewModel.SetErrors(Enumerable.Repeat("error", 1));
-            Assert.True(viewModel.HasNotifiedErrorsChanged);
-        }
-
-        #endregion
-
-        #region HasErrors
-
-        [Fact]
-        public void HasErrors_is_true_when_validation_errors_exist()
-        {
-            var viewModel = new TestViewModel();
-            viewModel.SetErrors(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
-            Assert.True(viewModel.HasErrors);
-        }
-
-        [Fact]
-        public void HasErrors_is_false_when_no_validation_errors_exist()
-        {
-            var viewModel = new TestViewModel();
-            viewModel.SetErrors(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
-            viewModel.SetErrors(Enumerable.Empty<string>(), nameof(viewModel.Property));
-            Assert.False(viewModel.HasErrors);
-        }
-
-        [Fact]
-        public void HasErrors_does_not_set_IsDirty()
-        {
-            var viewModel = new TestViewModel();
-            viewModel.NotifyPropertyChangedExternal(nameof(viewModel.HasErrors));
-            Assert.False(viewModel.IsDirty);
-        }
-
-        [Fact]
-        public void HasErrors_gets_notified_before_errors_change()
-        {
-            var invokedPropertyChangingEvents = new List<string>();
-            var viewModel = new TestViewModel();
-            viewModel.PropertyChanging += (sender, args) => invokedPropertyChangingEvents.Add(args.PropertyName);
-            viewModel.SetErrors(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
-            Assert.Contains(nameof(viewModel.HasErrors), invokedPropertyChangingEvents);
-        }
-
-        [Fact]
-        public void HasErrors_gets_notified_after_errors_change()
-        {
-            var invokedPropertyChangedEvents = new List<string>();
-            var viewModel = new TestViewModel();
-            viewModel.PropertyChanged += (sender, args) => invokedPropertyChangedEvents.Add(args.PropertyName);
-            viewModel.SetErrors(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
-            Assert.Contains(nameof(viewModel.HasErrors), invokedPropertyChangedEvents);
-        }
-
-        #endregion
-
-        #region GetErrors
-
-        [Theory]
-        [InlineData(null, 2)]
-        [InlineData("", 2)]
-        [InlineData(nameof(TestViewModel.Property), 1)]
-        [InlineData("NotExistingProperty", 0)]
-        public void GetErrors_with_error(string propertyName, int expectedErrorCount)
-        {
-            var viewModel = new TestViewModel();
-            viewModel.SetErrors(Enumerable.Repeat("Value has to be at least 5.", 1), nameof(TestViewModel.Property));
-            viewModel.SetErrors(Enumerable.Repeat("Value has to be at least 5.", 1), nameof(TestViewModel.AnotherProperty));
-            Assert.Equal(Enumerable.Repeat("Value has to be at least 5.", expectedErrorCount), viewModel.GetErrors(propertyName));
-        }
-
-        [Theory]
-        [InlineData(null)]
-        [InlineData("")]
-        [InlineData(nameof(TestViewModel.Property))]
-        [InlineData("NotExistingProperty")]
-        public void GetErrors_without_error(string propertyName)
-        {
-            var viewModel = new TestViewModel();
-            viewModel.SetErrors(Enumerable.Repeat("Value has to be at least 5.", 1), nameof(TestViewModel.Property));
-            viewModel.SetErrors(Enumerable.Empty<string>(), nameof(viewModel.Property));
-            Assert.Empty(viewModel.GetErrors(propertyName));
-        }
-
-        [Theory]
-        [InlineData(null, 2)]
-        [InlineData("", 2)]
-        [InlineData(nameof(TestViewModel.Property), 1)]
-        [InlineData("NotExistingProperty", 0)]
-        public void INotifyDataErrorInfoGetErrors_with_error(string propertyName, int expectedErrorCount)
-        {
-            var viewModel = new TestViewModel();
-            viewModel.SetErrors(Enumerable.Repeat("Value has to be at least 5.", 1), nameof(TestViewModel.Property));
-            viewModel.SetErrors(Enumerable.Repeat("Value has to be at least 5.", 1), nameof(TestViewModel.AnotherProperty));
-            Assert.Equal(Enumerable.Repeat("Value has to be at least 5.", expectedErrorCount), ((INotifyDataErrorInfo)viewModel).GetErrors(propertyName));
-        }
-
-        [Theory]
-        [InlineData(null)]
-        [InlineData("")]
-        [InlineData(nameof(TestViewModel.Property))]
-        [InlineData("NotExistingProperty")]
-        public void INotifyDataErrorInfoGetErrors_without_error(string propertyName)
-        {
-            var viewModel = new TestViewModel();
-            viewModel.SetErrors(Enumerable.Repeat("Value has to be at least 5.", 1), nameof(TestViewModel.Property));
-            viewModel.SetErrors(Enumerable.Empty<string>(), nameof(viewModel.Property));
-            Assert.Empty(((INotifyDataErrorInfo)viewModel).GetErrors(propertyName));
-        }
-
-        #endregion
-
-        #region NotifyErrorsChanged
-
-        [Fact]
-        public void NotifyErrorsChanged_raises_event_on_ErrorsChanged()
-        {
-            var invokedErrorChangedEvents = new List<string>();
-            var viewModel = new TestViewModel();
-            viewModel.ErrorsChanged += (sender, args) => invokedErrorChangedEvents.Add(args.PropertyName);
-
-            viewModel.NotifyErrorsChangedExternal(nameof(viewModel.Property));
-
-            Assert.Equal(Enumerable.Repeat(nameof(viewModel.Property), 1), invokedErrorChangedEvents);
-        }
-
-        #endregion
-    }
-}
\ No newline at end of file
diff --git a/test/Smaragd.Tests/ViewModels/ViewModelTests.cs b/test/Smaragd.Tests/ViewModels/ViewModelTests.cs
index 86ff524..8e7cb90 100644
--- a/test/Smaragd.Tests/ViewModels/ViewModelTests.cs
+++ b/test/Smaragd.Tests/ViewModels/ViewModelTests.cs
@@ -6,6 +6,8 @@
 using NKristek.Smaragd.ViewModels;
 using NKristek.Smaragd.Helpers;
 using Xunit;
+using System.Linq;
+using System.Collections;
 
 namespace NKristek.Smaragd.Tests.ViewModels
 {
@@ -99,8 +101,80 @@ public ObservableCollection<int> IsDirtyIgnoredWeakValues
                 get => _isDirtyIgnoredWeakValues?.TargetOrDefault();
                 set => SetProperty(ref _isDirtyIgnoredWeakValues, value);
             }
+
+            public void NotifyPropertyChangingExternal(string propertyName)
+            {
+                NotifyPropertyChanging(propertyName);
+            }
+
+            public void NotifyPropertyChangedExternal(string propertyName)
+            {
+                NotifyPropertyChanged(propertyName);
+            }
+
+            public void SetErrorsExternal(IEnumerable errors, string propertyName)
+            {
+                SetErrors(errors, propertyName);
+            }
+        }
+
+        #region IsValid
+
+        [Fact]
+        public void IsValid_is_false_when_validation_errors_exist()
+        {
+            var viewModel = new TestViewModel();
+            viewModel.SetErrorsExternal(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
+            Assert.False(viewModel.IsValid);
+        }
+
+        [Fact]
+        public void IsValid_is_true_when_no_validation_errors_exist()
+        {
+            var viewModel = new TestViewModel();
+            viewModel.SetErrorsExternal(Enumerable.Repeat("error", 1), nameof(viewModel.Property));
+            viewModel.SetErrorsExternal(Enumerable.Empty<string>(), nameof(viewModel.Property));
+            Assert.True(viewModel.IsValid);
         }
 
+        [Fact]
+        public void IsValid_does_not_set_IsDirty()
+        {
+            var viewModel = new TestViewModel();
+            viewModel.NotifyPropertyChangedExternal(nameof(viewModel.IsValid));
+            Assert.False(viewModel.IsDirty);
+        }
+
+        [Fact]
+        public void IsValid_gets_notified_by_HasErrors()
+        {
+            var invokedPropertyChangingEvents = new List<string>();
+            var invokedPropertyChangedEvents = new List<string>();
+            var viewModel = new TestViewModel();
+            viewModel.PropertyChanging += (sender, args) => invokedPropertyChangingEvents.Add(args.PropertyName);
+            viewModel.PropertyChanged += (sender, args) => invokedPropertyChangedEvents.Add(args.PropertyName);
+
+            viewModel.NotifyPropertyChangingExternal(nameof(viewModel.HasErrors));
+            viewModel.NotifyPropertyChangedExternal(nameof(viewModel.HasErrors));
+
+            Assert.Contains(nameof(viewModel.IsValid), invokedPropertyChangingEvents);
+            Assert.Contains(nameof(viewModel.IsValid), invokedPropertyChangedEvents);
+        }
+
+        #endregion
+
+        #region HasErrors
+
+        [Fact]
+        public void HasErrors_does_not_set_IsDirty()
+        {
+            var viewModel = new TestViewModel();
+            viewModel.NotifyPropertyChangedExternal(nameof(viewModel.HasErrors));
+            Assert.False(viewModel.IsDirty);
+        }
+
+        #endregion
+
         #region IsDirty
 
         [Theory]