diff --git a/src/Fdc3/IIntentResolution.cs b/src/Fdc3/IIntentResolution.cs
index 954bdf5..38c29ee 100644
--- a/src/Fdc3/IIntentResolution.cs
+++ b/src/Fdc3/IIntentResolution.cs
@@ -36,6 +36,6 @@ public interface IIntentResolution
         /// </summary>
         string? Version { get; }
 
-        Task<IIntentResult> GetResult();
+        Task<IIntentResult?> GetResult();
     }
 }
diff --git a/src/Fdc3/IntentResolution.cs b/src/Fdc3/IntentResolution.cs
index 88bb079..555be8d 100644
--- a/src/Fdc3/IntentResolution.cs
+++ b/src/Fdc3/IntentResolution.cs
@@ -44,6 +44,6 @@ public IntentResolution(IAppMetadata source, string intent, string? version = nu
         /// </summary>
         public string? Version { get; }
 
-        public abstract Task<IIntentResult> GetResult();
+        public abstract Task<IIntentResult?> GetResult();
     }
 }
diff --git a/src/Tests/Finos.Fdc3.Tests/IntentResolutionTests.cs b/src/Tests/Finos.Fdc3.Tests/IntentResolutionTests.cs
index fcd2764..e827b79 100644
--- a/src/Tests/Finos.Fdc3.Tests/IntentResolutionTests.cs
+++ b/src/Tests/Finos.Fdc3.Tests/IntentResolutionTests.cs
@@ -55,7 +55,7 @@ public MockIntentResolution(IAppMetadata source, string intent, string? version
         {
         }
 
-        public override Task<IIntentResult> GetResult()
+        public override Task<IIntentResult?> GetResult()
         {
             throw new NotImplementedException();
         }