diff --git a/.gitignore b/.gitignore
index 44f8545..2597431 100644
--- a/.gitignore
+++ b/.gitignore
@@ -64,3 +64,4 @@ NUnit-Frame-Report
 NUnit-NoFrame-Report
 Mock-Frame-Report
 Mock-NoFrame-Report
+/src/.vs
diff --git a/src/Tasks/ValidateXmlTask.cs b/src/Tasks/ValidateXmlTask.cs
index a193f3a..7ff471d 100644
--- a/src/Tasks/ValidateXmlTask.cs
+++ b/src/Tasks/ValidateXmlTask.cs
@@ -58,6 +58,17 @@ public class ValidateXmlTask : Task {
 
         #region Public Instance Properties
 
+        /// <summary>
+        /// Report warnings as errors.
+        /// </summary>
+        [TaskAttribute("failonwarn")]
+        [BooleanValidator]
+        public bool FailOnWarn
+        {
+            get;
+            set;
+        }
+
         /// <summary>
         /// The XML files that must be validated.
         /// </summary>
@@ -157,6 +168,10 @@ private void OnValidationError(object sender, ValidationEventArgs args) {
                 case XmlSeverityType.Warning:
                     // output error message
                     Log(Level.Info, "Validation warning: {0}", args.Message);
+                    if (this.FailOnWarn)
+                    {
+                        _numErrors++;
+                    }
                     break;
             }
         }