diff --git a/src/Microsoft.AspNet.Antiforgery/AntiforgeryValidationException.cs b/src/Microsoft.AspNet.Antiforgery/AntiforgeryValidationException.cs
new file mode 100644
index 0000000000..d5ea22e52b
--- /dev/null
+++ b/src/Microsoft.AspNet.Antiforgery/AntiforgeryValidationException.cs
@@ -0,0 +1,23 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+
+namespace Microsoft.AspNet.Antiforgery
+{
+    /// <summary>
+    /// The <see cref="Exception"/> that is thrown when the antiforgery token validation fails.
+    /// </summary>
+    public class AntiforgeryValidationException : Exception
+    {
+        /// <summary>
+        /// Creates a new instance of <see cref="AntiforgeryValidationException"/> with the specified
+        /// exception <paramref name="message"/>.
+        /// </summary>
+        /// <param name="message">The message that describes the error.</param>
+        public AntiforgeryValidationException(string message)
+            : base(message)
+        {
+        }
+    }
+}
diff --git a/src/Microsoft.AspNet.Antiforgery/DefaultAntiforgeryTokenGenerator.cs b/src/Microsoft.AspNet.Antiforgery/DefaultAntiforgeryTokenGenerator.cs
index 8cd2160238..ae43f846b6 100644
--- a/src/Microsoft.AspNet.Antiforgery/DefaultAntiforgeryTokenGenerator.cs
+++ b/src/Microsoft.AspNet.Antiforgery/DefaultAntiforgeryTokenGenerator.cs
@@ -119,13 +119,13 @@ namespace Microsoft.AspNet.Antiforgery
             // Do the tokens have the correct format?
             if (!cookieToken.IsCookieToken || requestToken.IsCookieToken)
             {
-                throw new InvalidOperationException(Resources.AntiforgeryToken_TokensSwapped);
+                throw new AntiforgeryValidationException(Resources.AntiforgeryToken_TokensSwapped);
             }
 
             // Are the security tokens embedded in each incoming token identical?
             if (!object.Equals(cookieToken.SecurityToken, requestToken.SecurityToken))
             {
-                throw new InvalidOperationException(Resources.AntiforgeryToken_SecurityTokenMismatch);
+                throw new AntiforgeryValidationException(Resources.AntiforgeryToken_SecurityTokenMismatch);
             }
 
             // Is the incoming token meant for the current user?
@@ -153,20 +153,20 @@ namespace Microsoft.AspNet.Antiforgery
 
             if (!comparer.Equals(requestToken.Username, currentUsername))
             {
-                throw new InvalidOperationException(
+                throw new AntiforgeryValidationException(
                     Resources.FormatAntiforgeryToken_UsernameMismatch(requestToken.Username, currentUsername));
             }
 
-            if (!Equals(requestToken.ClaimUid, currentClaimUid))
+            if (!object.Equals(requestToken.ClaimUid, currentClaimUid))
             {
-                throw new InvalidOperationException(Resources.AntiforgeryToken_ClaimUidMismatch);
+                throw new AntiforgeryValidationException(Resources.AntiforgeryToken_ClaimUidMismatch);
             }
 
             // Is the AdditionalData valid?
             if (_additionalDataProvider != null &&
                 !_additionalDataProvider.ValidateAdditionalData(httpContext, requestToken.AdditionalData))
             {
-                throw new InvalidOperationException(Resources.AntiforgeryToken_AdditionalDataCheckFailed);
+                throw new AntiforgeryValidationException(Resources.AntiforgeryToken_AdditionalDataCheckFailed);
             }
         }
 
diff --git a/src/Microsoft.AspNet.Antiforgery/DefaultAntiforgeryTokenStore.cs b/src/Microsoft.AspNet.Antiforgery/DefaultAntiforgeryTokenStore.cs
index 2b347a6ac8..ee677af059 100644
--- a/src/Microsoft.AspNet.Antiforgery/DefaultAntiforgeryTokenStore.cs
+++ b/src/Microsoft.AspNet.Antiforgery/DefaultAntiforgeryTokenStore.cs
@@ -68,7 +68,7 @@ namespace Microsoft.AspNet.Antiforgery
             var requestCookie = httpContext.Request.Cookies[_options.CookieName];
             if (string.IsNullOrEmpty(requestCookie))
             {
-                throw new InvalidOperationException(
+                throw new AntiforgeryValidationException(
                     Resources.FormatAntiforgery_CookieToken_MustBeProvided(_options.CookieName));
             }
 
@@ -92,19 +92,19 @@ namespace Microsoft.AspNet.Antiforgery
                 if (_options.HeaderName == null)
                 {
                     var message = Resources.FormatAntiforgery_FormToken_MustBeProvided(_options.FormFieldName);
-                    throw new InvalidOperationException(message);
+                    throw new AntiforgeryValidationException(message);
                 }
                 else if (!httpContext.Request.HasFormContentType)
                 {
                     var message = Resources.FormatAntiforgery_HeaderToken_MustBeProvided(_options.HeaderName);
-                    throw new InvalidOperationException(message);
+                    throw new AntiforgeryValidationException(message);
                 }
                 else
                 {
                     var message = Resources.FormatAntiforgery_RequestToken_MustBeProvided(
                         _options.FormFieldName,
                         _options.HeaderName);
-                    throw new InvalidOperationException(message);
+                    throw new AntiforgeryValidationException(message);
                 }
             }
 
diff --git a/test/Microsoft.AspNet.Antiforgery.FunctionalTests/AntiforgerySampleTest.cs b/test/Microsoft.AspNet.Antiforgery.FunctionalTests/AntiforgerySampleTest.cs
index 4135a56bd3..32431f6801 100644
--- a/test/Microsoft.AspNet.Antiforgery.FunctionalTests/AntiforgerySampleTest.cs
+++ b/test/Microsoft.AspNet.Antiforgery.FunctionalTests/AntiforgerySampleTest.cs
@@ -43,13 +43,13 @@ namespace Microsoft.AspNet.Antiforgery.FunctionalTests
             var httpRequestMessage = new HttpRequestMessage(HttpMethod.Post, "http://localhost/api/items");
 
             // Act
-            var exception = await Assert.ThrowsAsync<InvalidOperationException>(async () =>
+            var exception = await Assert.ThrowsAsync<AntiforgeryValidationException>(async () =>
             {
                 var response = await Client.SendAsync(httpRequestMessage);
             });
 
             // Assert
-            Assert.Contains("required antiforgery cookie", exception.Message);
+            Assert.Contains("The required antiforgery cookie \"3Cs-jwHTMFk\" is not present.", exception.Message);
         }
 
         [Fact]
diff --git a/test/Microsoft.AspNet.Antiforgery.Test/DefaultAntiforgeryTokenGeneratorTest.cs b/test/Microsoft.AspNet.Antiforgery.Test/DefaultAntiforgeryTokenGeneratorTest.cs
index 4813d68411..005f00f10c 100644
--- a/test/Microsoft.AspNet.Antiforgery.Test/DefaultAntiforgeryTokenGeneratorTest.cs
+++ b/test/Microsoft.AspNet.Antiforgery.Test/DefaultAntiforgeryTokenGeneratorTest.cs
@@ -303,7 +303,7 @@ namespace Microsoft.AspNet.Antiforgery
 
             // Act & assert
             var ex1 =
-                Assert.Throws<InvalidOperationException>(
+                Assert.Throws<AntiforgeryValidationException>(
                     () => tokenProvider.ValidateTokens(httpContext, fieldtoken, fieldtoken));
             Assert.Equal(
                 "Validation of the provided antiforgery token failed. " +
@@ -311,7 +311,7 @@ namespace Microsoft.AspNet.Antiforgery
                 ex1.Message);
 
             var ex2 =
-                Assert.Throws<InvalidOperationException>(
+                Assert.Throws<AntiforgeryValidationException>(
                     () => tokenProvider.ValidateTokens(httpContext, cookieToken, cookieToken));
             Assert.Equal(
                 "Validation of the provided antiforgery token failed. " +
@@ -334,7 +334,7 @@ namespace Microsoft.AspNet.Antiforgery
                 additionalDataProvider: null);
 
             // Act & Assert
-            var exception = Assert.Throws<InvalidOperationException>(
+            var exception = Assert.Throws<AntiforgeryValidationException>(
                     () => tokenProvider.ValidateTokens(httpContext, cookieToken, fieldtoken));
             Assert.Equal(
                 @"The antiforgery cookie token and request token do not match.",
@@ -369,7 +369,7 @@ namespace Microsoft.AspNet.Antiforgery
                 additionalDataProvider: null);
 
             // Act & Assert
-            var exception = Assert.Throws<InvalidOperationException>(
+            var exception = Assert.Throws<AntiforgeryValidationException>(
                     () => tokenProvider.ValidateTokens(httpContext, cookieToken, fieldtoken));
             Assert.Equal(
                 @"The provided antiforgery token was meant for user """ + embeddedUsername +
@@ -403,7 +403,7 @@ namespace Microsoft.AspNet.Antiforgery
                 additionalDataProvider: null);
 
             // Act & assert
-            var exception = Assert.Throws<InvalidOperationException>(
+            var exception = Assert.Throws<AntiforgeryValidationException>(
                     () => tokenProvider.ValidateTokens(httpContext, cookieToken, fieldtoken));
             Assert.Equal(
                 @"The provided antiforgery token was meant for a different claims-based user than the current user.",
@@ -436,7 +436,7 @@ namespace Microsoft.AspNet.Antiforgery
                 additionalDataProvider: mockAdditionalDataProvider.Object);
 
             // Act & assert
-            var exception = Assert.Throws<InvalidOperationException>(
+            var exception = Assert.Throws<AntiforgeryValidationException>(
                     () => tokenProvider.ValidateTokens(httpContext, cookieToken, fieldtoken));
             Assert.Equal(@"The provided antiforgery token failed a custom data check.", exception.Message);
         }
diff --git a/test/Microsoft.AspNet.Antiforgery.Test/DefaultAntiforgeryTokenStoreTest.cs b/test/Microsoft.AspNet.Antiforgery.Test/DefaultAntiforgeryTokenStoreTest.cs
index 585c42e171..61660652ab 100644
--- a/test/Microsoft.AspNet.Antiforgery.Test/DefaultAntiforgeryTokenStoreTest.cs
+++ b/test/Microsoft.AspNet.Antiforgery.Test/DefaultAntiforgeryTokenStoreTest.cs
@@ -112,7 +112,7 @@ namespace Microsoft.AspNet.Antiforgery
             // Arrange
             var mockHttpContext = GetMockHttpContext(_cookieName, "invalid-value");
 
-            var expectedException = new InvalidOperationException("some exception");
+            var expectedException = new AntiforgeryValidationException("some exception");
             var mockSerializer = new Mock<IAntiforgeryTokenSerializer>();
             mockSerializer
                 .Setup(o => o.Deserialize("invalid-value"))
@@ -128,7 +128,7 @@ namespace Microsoft.AspNet.Antiforgery
                 tokenSerializer: mockSerializer.Object);
 
             // Act & assert
-            var ex = Assert.Throws<InvalidOperationException>(() => tokenStore.GetCookieToken(mockHttpContext));
+            var ex = Assert.Throws<AntiforgeryValidationException>(() => tokenStore.GetCookieToken(mockHttpContext));
             Assert.Same(expectedException, ex);
         }
 
@@ -179,7 +179,7 @@ namespace Microsoft.AspNet.Antiforgery
                 tokenSerializer: Mock.Of<IAntiforgeryTokenSerializer>());
 
             // Act
-            var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+            var exception = await Assert.ThrowsAsync<AntiforgeryValidationException>(
                 async () => await tokenStore.GetRequestTokensAsync(httpContext));
 
             // Assert         
@@ -212,7 +212,7 @@ namespace Microsoft.AspNet.Antiforgery
                 tokenSerializer: new DefaultAntiforgeryTokenSerializer(new EphemeralDataProtectionProvider()));
 
             // Act
-            var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+            var exception = await Assert.ThrowsAsync<AntiforgeryValidationException>(
                 async () => await tokenStore.GetRequestTokensAsync(httpContext));
 
             // Assert         
@@ -315,7 +315,7 @@ namespace Microsoft.AspNet.Antiforgery
                 tokenSerializer: new DefaultAntiforgeryTokenSerializer(new EphemeralDataProtectionProvider()));
 
             // Act
-            var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+            var exception = await Assert.ThrowsAsync<AntiforgeryValidationException>(
                 async () => await tokenStore.GetRequestTokensAsync(httpContext));
 
             // Assert
@@ -346,7 +346,7 @@ namespace Microsoft.AspNet.Antiforgery
                 tokenSerializer: Mock.Of<IAntiforgeryTokenSerializer>());
 
             // Act
-            var exception = await Assert.ThrowsAsync<InvalidOperationException>(
+            var exception = await Assert.ThrowsAsync<AntiforgeryValidationException>(
                 async () => await tokenStore.GetRequestTokensAsync(httpContext));
 
             // Assert