diff --git a/src/Microsoft.AspNet.Mvc.ModelBinding/Internal/PrefixContainer.cs b/src/Microsoft.AspNet.Mvc.ModelBinding/Internal/PrefixContainer.cs
index bff1266b74..2192b9788a 100644
--- a/src/Microsoft.AspNet.Mvc.ModelBinding/Internal/PrefixContainer.cs
+++ b/src/Microsoft.AspNet.Mvc.ModelBinding/Internal/PrefixContainer.cs
@@ -13,25 +13,15 @@ namespace Microsoft.AspNet.Mvc.ModelBinding.Internal
         private readonly ICollection<string> _originalValues;
         private readonly string[] _sortedValues;
 
-        internal PrefixContainer(ICollection<string> values)
+        internal PrefixContainer([NotNull] ICollection<string> values)
         {
-            if (values == null)
-            {
-                throw new ArgumentNullException("values");
-            }
-
             _originalValues = values;
             _sortedValues = _originalValues.ToArrayWithoutNulls();
             Array.Sort(_sortedValues, StringComparer.OrdinalIgnoreCase);
         }
 
-        internal bool ContainsPrefix(string prefix)
+        internal bool ContainsPrefix([NotNull] string prefix)
         {
-            if (prefix == null)
-            {
-                throw new ArgumentNullException("prefix");
-            }
-
             if (prefix.Length == 0)
             {
                 return _sortedValues.Length > 0; // only match empty string when we have some value
diff --git a/src/Microsoft.AspNet.Mvc.ModelBinding/Validation/AssociatedValidatorProvider.cs b/src/Microsoft.AspNet.Mvc.ModelBinding/Validation/AssociatedValidatorProvider.cs
index e43f4fef0b..b79f817f77 100644
--- a/src/Microsoft.AspNet.Mvc.ModelBinding/Validation/AssociatedValidatorProvider.cs
+++ b/src/Microsoft.AspNet.Mvc.ModelBinding/Validation/AssociatedValidatorProvider.cs
@@ -6,13 +6,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 {
     public abstract class AssociatedValidatorProvider : IModelValidatorProvider
     {
-        public IEnumerable<IModelValidator> GetValidators(ModelMetadata metadata)
+        public IEnumerable<IModelValidator> GetValidators([NotNull] ModelMetadata metadata)
         {
-            if (metadata == null)
-            {
-                throw new ArgumentNullException("metadata");
-            }
-
             if (metadata.ContainerType != null && !string.IsNullOrEmpty(metadata.PropertyName))
             {
                 return GetValidatorsForProperty(metadata);
diff --git a/src/Microsoft.AspNet.Mvc.ModelBinding/Validation/DataAnnotationsModelValidator.cs b/src/Microsoft.AspNet.Mvc.ModelBinding/Validation/DataAnnotationsModelValidator.cs
index 79225d8a09..ec2d9e608d 100644
--- a/src/Microsoft.AspNet.Mvc.ModelBinding/Validation/DataAnnotationsModelValidator.cs
+++ b/src/Microsoft.AspNet.Mvc.ModelBinding/Validation/DataAnnotationsModelValidator.cs
@@ -7,13 +7,8 @@ namespace Microsoft.AspNet.Mvc.ModelBinding
 {
     public class DataAnnotationsModelValidator : IModelValidator
     {
-        public DataAnnotationsModelValidator(ValidationAttribute attribute)
+        public DataAnnotationsModelValidator([NotNull] ValidationAttribute attribute)
         {
-            if (attribute == null)
-            {
-                throw new ArgumentNullException("attribute");
-            }
-
             Attribute = attribute;
         }