diff --git a/Specification/src/Ardalis.Specification/ISpecification.cs b/Specification/src/Ardalis.Specification/ISpecification.cs
index 9a57af04..ba92eff7 100644
--- a/Specification/src/Ardalis.Specification/ISpecification.cs
+++ b/Specification/src/Ardalis.Specification/ISpecification.cs
@@ -31,6 +31,11 @@ public interface ISpecification<T, TResult> : ISpecification<T>
   /// <typeparam name="T">The type being queried against.</typeparam>
   public interface ISpecification<T>
   {
+    /// <summary>
+    /// Arbitrary state to be accessed from builders and evaluators.
+    /// </summary>
+    IDictionary<string, object> Items { get; set; }
+
     /// <summary>
     /// The collection of filters.
     /// </summary>
diff --git a/Specification/src/Ardalis.Specification/Specification.cs b/Specification/src/Ardalis.Specification/Specification.cs
index d32dc03b..0e414367 100644
--- a/Specification/src/Ardalis.Specification/Specification.cs
+++ b/Specification/src/Ardalis.Specification/Specification.cs
@@ -73,6 +73,9 @@ public virtual bool IsSatisfiedBy(T entity)
       return Validator.IsValid(entity, this);
     }
 
+    /// <inheritdoc/>
+    public IDictionary<string, object> Items { get; set; } = new Dictionary<string, object>();
+
     /// <inheritdoc/>
     public IEnumerable<WhereExpressionInfo<T>> WhereExpressions { get; } = new List<WhereExpressionInfo<T>>();